Automated semiconductor processing systems

ABSTRACT

A semiconductor processing system for wafers or other semiconductor articles. The system uses an interface section at an end of the machine accessible from the clean room. A plurality of processing stations are arranged away from the clean room interface. A transfer subsystem removes wafers from supporting carriers, and positions both the wafers and carriers onto a carrousel which is used as an inventory storage. Wafers are shuttled between the inventory and processing stations by a robotic conveyor which is oriented to move toward and away from the interface end. The system processes the wafers without wafer carriers.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.09/845,458, filed Apr. 30, 2001 and now pending, which is a continuationof U.S. patent application Ser. No. 09/187,652, filed Nov. 6, 1998 andnow abandoned, which is a continuation of U.S. patent application Ser.No. 08/851,480 filed May 5, 1997 and now abandoned, which is acontinuation of U.S. patent application Ser. No. 08/680,463, filed Jul.15, 1996, now U.S. Pat. No. 5,644,337, which is a continuation-in-partof U.S. patent application Ser. No. 08/622,349, filed Mar. 26, 1996, nowU.S. Pat. No. 5,784,797, which is a continuation-in-part of U.S. patentapplication Ser. No. 08/415,927, filed Mar. 31, 1995, now U.S. Pat. No.5,660,517, which is a continuation-in-part of Ser. No. 08/236,424, filedApr. 28, 1994, now U.S. Pat. No. 5,544,421. This application is also acontinuation of U.S. patent application Ser. No. 08/698,034, filed Aug.15, 1996, and now U.S. Pat. No. 5,836,736, which is a division of U.S.patent application Ser. No. 08/415,927, filed Mar. 31, 1995, now U.S.Pat. No. 5,660,517, which is a continuation-in-part of U.S. patentapplication Ser. No. 08/236,424, filed Apr. 28, 1994, now U.S. Pat. No.5,544,421. Applicants claim priority to these applications under 35U.S.C. §120.

TECHNICAL FIELD

This invention relates to automated semiconductor wafer processingsystems for performing liquid and gaseous processing of wafers. Suchsystems can be used to process semiconductor wafers, data disks,semiconductor substrates and similar articles requiring very lowcontaminant levels.

BACKGROUND OF THE INVENTION

The processing of semiconductor wafers has become of great economicsignificance due to the large volume of integrated circuits, data disks,and similar articles being produced.

The size of features used in integrated circuits and data disks havedecreased significantly, thus providing greater integration and greatercapacity. This has been possible due to improved lithography techniquesand improved processing.

The reduction in feature size has been limited by contamination. This istrue because various contaminating particles, crystals, metals andorganics lead to defects in the resulting products. The limitations onfeature size caused by contaminants have prevented fill utilization ofthe resolution capability of known lithography techniques.

Thus there remains an acute need for improved methods and systems forprocessing semiconductor wafers, data disks and similar articlesrequiring very low levels of contamination during processing.

During the fabrication of semiconductor components, variousmanufacturing steps involve the application of processing liquids andgases to the articles being processed. The application and removal ofthese processing fluids to and from the exposed surfaces of the wafersare enhanced by movement of the wafers within the processing chamber.Processing is also enhanced by centrifugal action of the semiconductorwafers which improves movement of fluids across the wafer surfaces, suchas when liquids are sprayed upon the wafer and then move across thewafer surfaces due to centrifugal forces acting upon the liquids as thewafers spin.

As one example, after semiconductor wafers have been cleaned, they mustbe dried. This is not a trivial process because any water that remainson the surface of a semiconductor wafer has at least some potential ofleaving some form of residue which may interfere with subsequentoperations or cause defects in the resulting products. Centrifugalaction aids in the removal of water and other processing liquids so thatsuch residues are not as likely to occur because the fluid is applied tothe surface and then moves outwardly and is removed from the surfaces.Drying is also benefitted because less liquid remains on the wafersurfaces, so drying speed is increased. This saves processing time andreduces the risk of residue or contamination due to particle adhesion.

In one type of prior art centrifugal processor, several wafer carriersare put in holders or carriers in a spaced substantially circular arrayaround the axis of rotation. The rotor with loaded carriers of wafers isthen rotated within a processing chamber which is typically enclosedwithin a processing bowl or vessel. In the center of the vessel and atother peripheral locations are fluid manifolds with spray nozzles orsimilar inlets that are connected to a source of deionized water, heatednitrogen, or other processing chemicals both liquids and gases. These orother processing fluids are thus applied to the wafers to effectwashing, drying or other processing.

Other prior art spin rinser dryers have been built for drying batches ofwafers held in a single wafer carrier. The wafer carrier and supportedwafers are held within a rotor. The rotor has an opening for receivingthe carrier with the wafers positioned in an array with the centerpointsof the wafers at or nearly aligned with the axis of rotation. Typicallya small offset is used so that the wafers will seat into the wafercarriers as centrifugal forces are developed during rotation. The water,nitrogen or other processing fluids come into the chamber along thesides rather than through a manifold mounted at the center. The rinsing,other liquids application, or drying take place as the rotor spins withthe carrier and wafers held therein. Stationary retainer bars aretypically provided adjacent the open top side of the wafer carrier toprevent the wafers from being displaced if the rotor should stop in anupside-down position. The rotors are also typically controlled to stopin a right-side-up position. This type of spin rinser dryer is normallytermed an axial or on-axis spin rinser dryer.

Additionally semiconductor processing machines of similar configurationare also used for centrifugal chemical etching or other chemicalprocessing. In this regard, the required chemicals are pressurized orpumped to the processing chamber and valves control the supply of suchchemicals into the chamber. The chemical processing can be following byassociated rinsing and drying operations. The application of processingchemicals adds to the complexity of the processing because highlyreactive chemicals may impinge upon the wafer surfaces at differentangles, fluid velocities, with differing flow rates, and with otherdynamically varying effects. This variability can cause different etchrates or other variations in chemical processing which is difficult toovercome.

Process uniformity within a batch and repeatability from batch to batchhave been major considerations in semiconductor processing, and inparticular centrifugal semiconductor processing. The issue isparticularly of interest in the case of batch centrifugal processingbecause the wafers are held in closely spaced arrays using wafercarriers. In addition to inherent variations in the application ofprocessing fluids to the wafers, there are also variations associatedwith how wafers are held within the carriers. The structural parts ofthe carriers necessarily restrict access of fluids to the wafersurfaces. This has almost invariably led to different processing resultsfor wafers in different positions within a carrier, even thoughprocessing has occurred in the same batch. Although carriers have beendesigned to reduce their effects on processing fluid distribution withinthe processing chamber, it has been impossible to eliminate theireffects on uniformity and repeatability of processing results.

While the apparatus and methods utilized heretofore have operated withvarying degrees of success, they have also sometimes suffered problemswith regard to contamination or particle additions which can occurduring processing. As the features and geometries of the discretecomponents formed on the semiconductor devices have become smaller andmore densely packed, the need for more stringent contamination controlhas become increasingly difficult.

Thus there has been a need in the art of semiconductor wafer and similararticle processing for a centrifugal processing machine which providesimproved uniformity of process results while minimizing the possibilityof contamination. This must be done without substantial risk of damageto the semiconductor wafers.

A further area of significance in the processing of semiconductorarticles includes the handling and coordination of wafer carrierscommonly used to support semiconductor wafers in various stages ofprocessing and translocation between processes. Wafer carriers are oftensusceptible to picking up undesirable contaminants. Carriers which havebeen contaminated can in some processing schemes be used to carry morethan one batch of wafers. This increases the potential for spreadingcontamination amongst multiple wafers and batches.

These and other considerations have led to a novel semiconductorprocessing system as described herein, with various benefits andadvantages which are described or inherent from the construction anddescription given herein.

BRIEF DESCRIPTION OF THE DRAWINGS

One or more preferred forms in the invention are described herein withreference to the accompanying drawings. The drawings are brieflydescribed below.

FIG. 1 is a perspective view showing a preferred semiconductorprocessing system according to the present invention.

FIG. 2 is a perspective view similar to FIG. 1 showing the preferredsemiconductor processing system with portions broken away to betterillustrate some of the principal components thereof.

FIG. 3 is a front elevational view of the processing system of FIG. 1.

FIG. 4 is a partial side elevational view of portions of the interfacesection of the processing system of FIG. 1.

FIG. 5 is a perspective view showing selected components of theprocessing system of FIG. 1.

FIG. 6 is a plan view showing selected components of the processingsystem of FIG. 1.

FIG. 7 is a perspective view showing a preferred carrousel subassemblyforming a part of the processing system of FIG. 1.

FIG. 8 is a perspective view showing a preferred article transfersubassembly forming a part of the processing system of FIG. 1.

FIGS. 9-21 are a series of views illustrating how the processing systemof FIG. 1 transfers semiconductor wafers onto the carrousel inpreparation for processing in the associated processing stations.

FIG. 22 is a perspective view of a transfer implement which is utilizedin the system of FIG. 1.

FIG. 23 is a perspective view of a preferred centrifugal processor rotorutilized in the system of FIG. 1.

FIG. 24 is a fragmentary, perspective view of the centrifugal processorrotor of FIG. 23, with the some portions removed to better showunderlying structures.

FIG. 25 is a fragmentary, perspective view of the centrifugal processorrotor shown in FIG. 23, at a processing step subsequent to that shown inFIG. 24. Some portions are removed to show the underlying structures.

FIG. 26 is a fragmentary, perspective view of the centrifugal processorrotor shown in FIG. 23, at a processing step subsequent to that shown inFIG. 25. Some portions are removed to show the underlying structures.

FIG. 27 is a fragmentary, perspective view of the centrifugal processorrotor shown in FIG. 23, at a processing step subsequent to that shown inFIG. 26. Some portions are removed to show the underlying structures.

FIG. 28 is a side elevational view showing a further embodiment of theinvention having a rotor and transfer implement mounted upon a roboticarm assembly.

FIG. 29 is a front elevational view of the rotor shown in FIG. 28.

FIG. 30 is a front elevational view similar to FIG. 29 with a transferimplement positioned in front of the rotor.

FIG. 31 is a perspective view showing portions of the rotor and transferimplement shown in FIG. 28.

FIG. 32 is a control system schematic block diagram of a preferredcontrol system used in the processing system of FIG. 1.

FIG. 33 is a perspective view showing another preferred semiconductorwafer processing system according to this invention.

FIG. 34 is a perspective view showing top portions of a wafer holdingtray used in the processing system of FIG. 33.

FIG. 35 is a perspective view showing bottom portions of a wafer holdingtray used in the processing system of FIG. 33.

FIG. 36 is a perspective view showing the tray of FIG. 34 loaded withwafers.

FIG. 37 is a perspective view showing a prior art industry standardwafer carrier loaded with wafers. The wafer holding tray of FIG. 34 ispositioned below the wafer carrier.

FIG. 38 is a perspective view showing portions of a wafer handlingsubsystem used in the processing system of FIG. 33.

FIG. 39 is a perspective view of the subsystem of FIG. 38 moved into aninitial loading position with wafer carriers containing wafers loadedthereon.

FIG. 40 is a perspective view showing the subsystem of FIG. 38 movedinto a further position wherein empty wafer trays are passing through atray pass-through opening.

FIG. 41 is a perspective view showing the subsystem of FIG. 38 movedinto a further position wherein the wafer trays have been elevated upthrough the wafer carriers to lift wafers from the carriers onto thetrays.

FIG. 42 is a perspective view showing the subsystem of FIG. 38 movedinto a still further position wherein the wafer trays with wafers arepositioned upon an upper carriage.

FIG. 43 is a perspective view showing the subsystem of FIG. 38 with theupper carriage and supported wafers and wafer trays positioned forholding until subsequently processed in the system processing chambers.

FIG. 44 is a perspective view of the subsystem of FIG. 38 in a positionsimilar to FIG. 39 with the emptied wafer carriers ready for removal andreplacement by loaded wafer carriers so that a second group can betransferred in a process similar to that illustrated by FIGS. 39-44.

FIG. 45 is a perspective view showing the wafer processing system ofFIG. 33 with a robot conveyor loading a tray of wafers.

FIG. 46 is a perspective view similar to FIG. 45 with the robot conveyorrelocated and preparing to install the tray wafers into a centrifugalprocessing module.

FIG. 47 is a perspective view similar to FIG. 46 with the robot extendedinto a loading position wherein the tray of wafers is installed in thecentrifugal processing module.

FIG. 48 is a top view showing a hand portion of the mechanical armassembly with a tray of wafers loaded thereon.

FIG. 49 is a front view showing the hand portion of FIG. 48.

FIG. 50 is an isometric view of a preferred centrifugal processing rotorused in the centrifugal processing modules shown in FIG. 33.

FIG. 51 is a front view of the rotor shown in FIG. 31.

FIG. 52 is a front view of the rotor as shown in FIG. 51 with a wafertray held within the rotor.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Processing System Generally

FIGS. 1 and 2 generally show a preferred processing system 11constructed in accordance with the novel aspects of the inventions. Theprocessing system includes a frame 13 which is connected with a housing12. The housing 12 and frame 13 rests upon a supporting surface (notshown). The housing is most preferably constructed to form an enclosurewhich is substantially or fully encloses the machine and defines aworking space 18 within which the wafers 80 or other semiconductorarticles are moved and processed in relative protection from dust andcontamination.

FIG. 1 does not show the full enclosure of housing 12 to improve theillustration. Specifically, the top or roof has been removed forpurposes of illustration. The roof can advantageously be provided with aseries of ultrafine filters (not shown) through which air, nitrogen orother work space gas is supplied to working space 18.

FIG. 1 shows that the processing system 11 includes an interface section14 which includes mechanisms and features for inputting and outputtingthe wafers 80 or other semiconductor articles being processed. Theinterface section also includes mechanisms for transferring wafers fromwafer carriers 79 and for inventorying both the wafers and carriers upona carrousel 720. Preferred forms of these mechanisms will be describedin detail below after further introduction of some additional basicfeatures of the processing system.

Processing Stations Generally

Processing system 11 also includes a processing section 8. Theprocessing section includes one or more individual processing stations19 which can be of various constructions. Centrifugal or immersion typestations can be used. In a preferred form of the invention, theprocessing stations 19 are each centrifugal processing stations whichinclude a processing vessel 201 which partially encloses a processingchamber defined therewithin. The processing vessels also preferably matewith a movable door 202 which can be moved between the closed positionsgenerally shown and the retracted position shown at one station in FIG.2.

The processing stations 19 are mounted within processing station console203 which have associated supporting fluid supplies for providingprocessing liquids and gases as needed for the particular processesbeing carried out at that station. Stations 19 can all be the same, eachbe different, or there can be more than one of a particular type coupledwith one or more other associated stations within the same processingsystem.

As shown, the semiconductor articles are processed in batches. Thewafers within a batch are arranged in a linear batch array in which theindividual wafers or other articles are spaced, substantially paralleland aligned with central normal axes of the disk-shaped wafers alignedto form a longitudinal central batch axis (axis not illustrated). Thesize of the wafers can vary. The number of wafers can also vary, but atthis time typically will include 25 or 50 wafers because industrystandard wafer carriers 79 have such capacities.

Robotic Conveyor

FIGS. 1 and 2 further show a robotic conveyor, which is generallyindicated by the numeral 15. Robotic conveyor 15 includes a mountingconveyor beam or rail 7 upon which a movable conveyor robot subassembly5 is mounted and moves relative to the rail. The conveyor 15 conveys thesemiconductor wafers or other articles 80 within the processing system,specifically between, to and from, the inventory carrousel 720 and theprocessing stations 19.

The robotic device can be of various designs. One design is thatavailable from Semitool, Inc. of Kalispell, Mont. as part of processingsystems sold under the trademark MAGNUM. Further detailed description ofsuitable conveyor devices and other aspects of the processing system canalso be implemented in a manner shown in described in U.S. Pat. Nos.5,544,421; 5,660,517; and 5,678,320 which are hereby incorporated byreference in their entirety. Such forms of apparatus are also describedin corresponding PCT Applications which were published by the WorldIntellectual Property Organization under PCT Publication Nos. WO95/30238; WO 95/30240; WO 30239; all of which are incorporated byreference.

In the preferred robotic transfer device 15 the construction includes anarticulated arm 16. FIG. 5 better illustrates that the preferredarticulated arm includes an upper arm portion 741, lower arm portion742, and hand portion 743. Articulated arm 16 uses hand 743 and anattached engagement head which can be oriented into various planes oforientation and various positions. The conveyor robot has a distal end17 which is used to mount an engagement implement which is preferably ofthe construction detailed below or equivalents thereto. The distal end17 may move along assorted courses of travel to deliver thesemiconductor articles to various individual or plural work stations 19.Each of these various courses of travel will be discussed in greaterdetail, hereinafter. While the present invention is described as beinguseful in combination with a washing or chemical processing stations, itwill be appreciated that the same device may find utility in otherapplications.

Input-Output Interface Section

FIGS. 1 and 2 also show that processing system 11 preferably includes aninput-output or interface section 14. The current invention in-partfocuses on the novel construction used for interface section 14.Interface section 14 is constructed using the processor framework 13 andenclosure wall structure 12. The interface section has a front end wall701 which is advantageously arranged along a hall or gallery within aclean room. Front wall 701 includes an interface opening 702. Interfaceopening 702 is provided with an interface door 703 which is preferablyat least partially transparent to allow observation by a human operator.Door 703 is preferably operated by a suitable power door operator 709which can be a linear screw drive or many other suitable mechanisms. Thefront wall 701 is also preferably provided with an operator controlmodule or station 704 which is accessible from the clean room end of thesystem and can be of various constructions. As shown, operator module704 includes a touch screen display and control panel 705. Alsoappropriately included are a disk drive 706 for providing controlprogramming information, and other manually depressible control buttons(such as emergency stop) not specifically shown, but generally referredto as 707.

Interface section 14 also preferably includes a carrousel supportframework 710 which is mounted in an elevated position within theinterface section enclosure. Carrousel support framework 710 includes acentral frame opening 711 (FIG. 1) which is used to mount an inventorycarrousel which will be more fully described below. The specific form ofthe carrousel support framework can easily vary depending upon thespecific form in which the carrousel or other inventory storage isconstructed.

Inventory Carrousel

FIG. 5 shows portions of the carrousel inventory mechanism used tosupport a plurality of wafers 80 or other semiconductor articles beingprocessed. Carrousel assembly 720 includes a carrousel mounting plate721 which is secured within opening 711 of the carrousel supportframework 710 using fasteners 729 (FIG. 6). Support plate 721 isconnected to and carries a carrousel main housing 722 which isdetachable for maintenance and other purposes. Carrousel main housing722 has internal features which support and mount a carrousel drivemotor 747 (shown in phantom in FIG. 7). The output of the carrouseldrive motor is in the form of a carrousel rotor shaft 723. The lower endof shaft 723 has a suitable angular position encoder 745 coupled at itslower end by coupling 746. An encoder support bracket 744 is attached toframe 13 or other suitable supporting structure to stabilize portions ofthe encoder against rotation with shaft 723.

The carrousel assembly further includes a plurality of carrousel supportarms 725 which extend outwardly and are arranged to provide fourcantilevered beam portions which can be advantageously used to supportwafers 80 and wafer carriers 79. As shown, the carrousel support arms725 connect in an overlapping square-shaped array to form a centralsquare 726 which is overlaid with a carrousel central support panel 727.

Each carrousel support arm 725 is preferably constructed so as toreceive one or more support brackets 728. Support brackets 728 can bemounted in any suitable fashion. As shown, support brackets 728 restover arms 725 and are secured thereto by fasteners (not shown).

Each support bracket 728 includes an upper or first rest or support 730,and a second or lower rest or support 731. The upper rest 730 ispreferably provided with a series of grooves or notches 732 (see FIG. 6)along opposing inner, upper surfaces. Grooves 732 serve as supportingreceivers into which are received individual wafers 80. The lower,second supports 731 are used for receiving and supporting wafer carriers79. As shown, the lower supports 731 are constructed so as to form asemiconductor article carrier support. Article carrier support 731 isadvantageously provided with constructional surface details (not shown)which serve to help retain the wafer carriers 79 against unintendedmovement after being placed upon supports 731. This maintains thecarriers in position when the carrousel rotor rotates to a desiredangular position. The specific features used will vary in conformancewith the particular carrier design used.

The interface section also preferably includes a mid-level deck 750which extends and portions which extend beneath such deck. Deck 750 ispreferably perforated using perforations or apertures (not shown) whichallow clean air or other work space gas to pass downwardly from upperair supply and filtration units (not shown) which provide filtered airinto upper reaches of the processing system enclosure. This arrangementtends to take any generated particles or contaminants downwardly in thestream of filtered air or other working space gas.

The preferred carrousel construction shown in FIGS. 5-7 illustrates asystem designed to accommodate approximately four hundred (400) wafers.Such wafers are typically supplied in wafer carriers 79 which have thecapacity of twenty five (25) wafers each. Carrousel 720 thus is capableof supporting both the wafers and sixteen (16) associated wafer carriersin inventory positions upon the carrousel. The carrousel constructionand arrangement shown allows the inventoried wafers and carriers to beproperly accessed at four different angular positions of the carrousel.Access can occur using either a wafer transfer apparatus 800 or roboticconveyor 15. This arrangement also allows the robotic conveyor to accessone arm of the carrousel while another arm of the carrousel is beingloaded or unloaded using the transfer subsystem 800.

Article Transfer Subsystem

The semiconductor article transfer mechanism 800 is shown in greaterdetail in FIG. 8. Mechanism 800 is advantageously supported by asubframe 802 which either forms part of machine framework 13 or isotherwise appropriately supported within the enclosure 12. Subframe 802can be of various constructions. FIG. 8 shows that subframe 802 includesa lateral stage guide rail 803 which mounts a laterally moveabletransfer main subassembly 810.

Lateral motion is provided to horizontally move the main subassembly 810back and forth using a suitable later stage drive. As shown, the lateralstage drive includes a lateral stage drive motor 804 which drives anassociated screw actuator or other suitable drive assembly which movesthe main subassembly 810 horizontally back and forth along support rail803. The Lateral stage drive operates directly upon the supporting frameguide 803 and a lateral stage follow 812 which forms a part of mainsubassembly 810. A variety of lateral stage guide and driveconstructions are suitable for use in this invention.

The article transfer main subassembly 810 also includes a main part 811.Main part 811 is mounted for elevation change such as by mounting forvertical motion relative to the lateral stage follower 812. Theconnection between lateral stage follower 812 and main piece 811 isactuated by a first elevator actuator 823 which is mounted within mainpart 811.

The lateral stage 812 and main part 811 together form a transfer firstcarriage which is mounted to the frame for movement relative thereto. Asshown, the first carriage is mounted for both horizontal and verticalmotion. The first carriage preferably includes at least one feature forsupporting at least one article carrier 79 on the first carriage. Thecarrier support features can be constructed according to a variety ofalternative designs; however, a preferred construction will be detailednext.

The article transfer mechanism 800 further includes two upper decks 831and 832 which form a part of the first carriage and are connected to themain part 811. As shown, first deck 831 is connected to the main part ina fixed relationship, although a moveable mounting is alternativelypossible. First deck 831 has two wafer carrier receptacles 833 formedtherein. Receptacles 833 are shaped and sized so as to support bottomedge surfaces of wafer carriers 79. Receptacles 833 also each have anopen portion or receptacle opening within the receptacle which is openthrough deck 831. These receptacle openings allows for the free passageof article lift heads 821 up through the receptacle and deck. The liftheads also pass up through an aperture formed in the bottom of carriers79 in order to lift wafers 80 from the wafer carriers 79.

As shown, the carrier support on the first carriage also includes asecond or upper deck 832. Second deck 832 also has receptacles 833 forreceiving wafer carriers 79 and supporting the carriers thereon.Receptacles 833 in the second deck also have openings which allow thewafer lift heads 821 to extend therethrough when elevated as explainedbelow. The lift heads 821 associated with the first deck can beconsidered a first set of lift heads, and those associated with thesecond deck can be considered a second set of lift heads. Although aplurality of lift heads is shown and preferred, it is alternativelypossible to use a single lift head and a single deck, with resultingreduced capacity of the transfer mechanism.

First and second decks 831 and 832 are advantageously provided with asuitable number of carrier positioners 846 which facilitate easyplacement of the carriers 79 into the receptacles 833. Carrier detectors847 are also advantageously included at receptacles 833 to allowdetection of the carriers when placed in a proper position within thereceptacles.

The first and second deck pieces 831 and 832 are advantageouslyconstructed, mounted and arranged so as to facilitate their loading withwafer carriers and wafers held in the carriers. This loading is intendedto occur through the interface opening 702. The loading isadvantageously done by bringing both decks into close proximity to theopening so that either a robotic or human operator can set the carriersloaded with wafers into receptacles 833 through opening 702. Tofacilitate this, the construction shown includes a first deck 831 andsecond deck 832 which are both capable of being placed adjacent opening702. Deck 831 is in closest proximity without special modification ormovement beyond that provided by the lateral stage in properlypositioning the subassembly 810 toward the opening 702. This isillustrated in FIG. 9. As FIG. 9 further shows, the second deck 832 isslidably connected to the first deck 831 or other parts of the main part811. FIG. 8 shows a preferred construction for accomplishing this whichuses a guide rail 840. Guide rail 840 slidably connects the two decksand allows linear motion in the direction substantially defined by thelongitudinal axis of guide rail 840. Second deck 832 is moved relativeto first deck 831 using an upper deck actuating driver or motor 842. Theactuator advantageously includes a linear drive, such as a helical screwand ball bearing follower which slides the upper deck relative to thelower deck to assume positions as is illustrated in more complete detailin FIGS. 9-12. The position shown in FIG. 9 is an overlapping positionin which the upper deck is positioned adjacent to the loading andunloading opening 702 for easy access. The position shown in FIG. 12depicts the upper deck in a staggered relationship with the lower deckwhich allows both decks to support wafer carriers thereon.

The transfer subassembly 810 also includes at least one second carriage.As shown, the second carriage includes the wafer lift heads 821described above. The lift heads serve as supports for wafers or othersemiconductor articles being transferred. In the exemplary constructionshown, the lift heads are supported upon upstanding lift head extensionrods 820. The lift heads and portions of the lifting rods extend throughthe openings in the receptacles 833, such as shown in FIG. 14.

In the preferred construction shown there are two second carriages. Oneof the second carriages include the first set of lift heads whichextends through the first deck 831. The other second carriage includesthe second set of lift heads which extend through the second deck 832.The second carriages are preferably operated in an independent mannerusing the construction which will now be described.

The second carriages also include transverse second carriage members813. The transverse second carriage members 813 form a connecting barwhich supports the lift rods 820 near the ends of each connecting bar.The connecting bars, lift rods and lift heads move upwardly anddownwardly as the parts of the second carriage assemblies. These secondcarriage assemblies are move by second carriage assembly operators. Inthe preferred construction, these operators include a suitable lineardrive mechanism, such as a helical screw drive. The drive shown in FIG.8 includes a drive motor 814 which drives a screw member 841. A screwdrive follower 842 is nonrotatably supported within a guide channel 843formed in the side of the main part 811. The transverse members 813 areconnected to the drive followers 842 by fasteners 844. This constructionprovides vertically moveable second carriage assemblies which each moveindependently relative to the main piece 811 using second carriageelevator motors 814.

It is further noteworthy that the wafer lift heads 821 are preferablyprovided with a series of wafer or other semiconductor article receivinggrooves or other similar receiving features 822 which allow an array ofwafers or other articles to be held therein.

Transfer of Wafers Between Carriers and Carrousel

FIGS. 9-21 illustrate the preferred operation and methods according tothe invention. The methods described in this section include loading theprocessor and those steps involved in transferring wafers 80 fromcarriers 79 to the carrousel array held by carrousel 720.

FIG. 9 shows an initial stage of the methods wherein the wafer transferhas been controlled by positioning the upper deck 832 of the transferfirst carriage toward the opening 702 (not shown in FIG. 9 see FIG. 1).The illustrated carriers 79 and supported wafers 80 are awaiting loadingonto the upper deck 832. The carriers are then manipulated manually orby machine to perform loading of the carrier or carriers through theopening 702 and onto the upper deck. The loading is preferably performedso as to provide positioning of the carriers onto the deck and into thecarrier support receptacles 833, or other features used to properlyposition the carriers upon the transfer first carriage.

After the carriers have been positioned upon upper deck 832, thenoperation preferably proceeds by retracting or otherwise moving theupper deck into the position shown in FIG. 12. This retracting stepallows access to the carrier receptacles 833 formed on the lower deck831. This causes a presenting of the second set of carrier receptaclesin preparation for loading of carriers thereon in the same manner asjust described above. FIG. 13 shows the second set of carriers loadedonto the lower deck 831. With this action the transfer mechanism isfully loaded with wafer carriers having wafers contained therein.

FIG. 14 illustrates the step of separating the wafer 80 or othersemiconductor articles from the carriers 79. The separating of thearticles from the carriers can be effected by raising or elevating thelifting heads 822. The raising or extending step is preferably poweredusing the second carriage operators 814 which lift the heads relative tothe first carriage of the transfer mechanism.

FIG. 15 shows a further stage of the transfer process wherein the twocarrier-loads over the upper deck 832 are moved to effect a positioningof the wafers over the wafer supports provided on the carrousel. Toeffect this step, the carrousel is adjusted as needed by moving thecarrousel angularly into the aligned pre-loading position shown in thatFig. Thereafter the step of translating the lateral stage of thetransfer mechanism toward the open wafer support brackets 728receptacles or receivers is performed. The first set of wafers is firstpositioned over the wafer supports on brackets 728 at the desiredpositions.

FIG. 16 then shows the upper deck lifting heads retracted downwardlyafter a retracting step has been performed upon the upper deck secondcarriage. This retracting step causes a downward lowering andtransferring of the wafers from the receiving grooves 822 in the liftingheads 821 to the receiving grooves 732 formed in the carrousel wafersupports 730.

FIG. 17 shows that the wafer lifted from the lower deck 831 aresimilarly transferred to the carrousel wafer supports. It should benoted that more efficient use of space is accomplished by placing thesecond set of wafers into closer proximity with the first set of wafers,than is otherwise allowed due to the size and geometry of the wafercarriers. This is indicated by elimination of the medial gap 850 (FIG.16) as indicated in FIG. 17. The result is to form two parallelcarrousel batch arrays each having fifty (50) or other suitable numberof wafers, starting with twenty five (25) from each wafer carrier.Although this configuration is preferred it is alternatively possible touse less or more numbers of carriers to form a single carrousel batcharray.

FIG. 18 shows the wafer transfer subassembly fully retracted away fromthe carrousel and prepared to accept another group of four (4) loadedwafer carriers to load another arm of the carrousel. Prior toundertaking such loading and transferring, the carrousel is affected bymoving the carrousel angularly as illustrated in FIG. 19. This rotatingof the carrousel also performs an aligning or positioning step so thatthe robotic wafer conveyer 15 can interact with the carrousel batcharrays.

FIG. 20 shows the robotic conveyor 15 after positioning the conveyorinto a carrousel engagement position. In this positioning step the waferengagement implement 140 is extended under the wafers held on thecarrousel. The conveyor then performs a lifting step which separates thewafers from their supported positions on brackets 728. The conveyor thenperforms a series of conveying movements, such as illustrated in FIG.21. The moving or conveying step is performed to relocate the wafersinto position for loading into the desired processing station 19. Morespecific explanation about the loading (installing) and unloading of thewafers into the processing stations 19 will be given below after firstconsidering the preferred construction of the engagement implements andcorresponding rotors which can advantageously be employed in theinvention.

First Processing Rotor and Transfer Implement

A first embodiment of preferred centrifugal processor rotor used in thepresent invention is generally indicated by the numeral 10 in FIG. 23.The centrifugal processor rotor forms part of the larger machine orprocessing system 11 described above.

FIGS. 24-27 show a first preferred embodiment of rotor 10 and articletransfer implement 140 in different positions in order to illustrate thevarious features of each and their cooperation to perform the noveloperational methods described herein. FIG. 22 shows the transferimplement 140 alone. FIG. 23 shows the rotor alone.

The centrifugal processor rotor 10 includes a rotor frame 20. The rotorframe has a front portion or plate 21 which is defined by a peripheraledge 22. The front portion 21 further defines a substantially centrallydisposed opening or aperture 23, and a pair of mounting apertures 24.The front portion or plate 21 has a forwardly facing surface 25, and anopposite rearward facing surface 26. Mounted in suitable relationship,such as the substantially parallel spaced relationship relative to thefront plate 21, is a rear portion or second plate 30. The rear portion30 has a peripheral edge 31, and further defines a major aperture 32,and a minor aperture 33. The minor aperture is disposed in substantiallycoaxial alignment relative to the axis of rotation of the rotor frame20.

The rear portion further defines a pair of mounting apertures 34. Therear portion 30 has a main body 35 which is substantially planar, andcircular in shape, and which has substantially the same diametricaldimensions as the front portion 21. The main body 35 is further definedby an exterior facing surface 36, and an opposite, interior facingsurface 37, respectively.

The individual front and rear portions 21 and 30, respectively, are heldtogether in a suitable construction, such as the illustratedsubstantially coaxial and parallel spaced relation by means of rotorframe members 40 which are spaced about the rotor. Each of the rotorframe members 40 have a first end 41, which is fixed on the frontportion 21 by utilizing conventional fastening methods, and an opposite,second or distal end 42, which is mounted on the rear portion 30 byusing the same techniques. The location of the first and second platesin the given orientation described above defines a processing cavity 43therebetween.

As best seen by reference to FIG. 23, a pair of laterally disposedsupport members, or combs 50 are borne by the rotor frame 20 and arepositioned in the cavity 43. The combs 50 include a first comb 51, andan opposite, second comb 52 which are individually affixed on theinterior facing surfaces 26 and 37 of the first and second portions 21,and 30 respectively. The first and second combs extend substantiallynormally outwardly relative to the surfaces 26 and 37, as shown. Thefirst and second combs 51 and 52 are disposed to hold the wafers orother semiconductor articles being processed. This can advantageously bein the form of the illustrated substantially parallel, spacedconfiguration shown.

Each of the first and second combs has a frame portion 53, which isaffixed on the front portion 21, and the rear portion 30, by usingconventional fastening techniques. Further, each of the first and secondcombs has a comb portion 54 which is defined by an undulating peripheraledge 55. The undulating peripheral edges 55 are positioned in inwardlyfacing relation, one to the other, and are operable to engage thesemiconductor articles as will be discussed in further detail in theparagraphs which follow. The peripheral edge may be provided in variousmaterials or with various surface coatings which will protect thesemiconductor articles which come into contact with same. One preferredconstruction utilizes a tetrafluoroethylene polymer plastic material.Others materials and constructions are alternatively possible.

FIG. 23 further shows a pair of base combs, identified hereinafter asfirst and second base combs 61 and 62, respectively. These base combsare affixed by conventional fastening techniques on the front and rearportions 21 and 30 respectively. The pair of base combs are showndisposed in parallel spaced relationship, and are generally aligned withthe rotational axis of the rotor. The first and second base combs, incombination with the first and second laterally disposed combs 51 and52, define an article receiving assembly or receiver 63 which isoperable to hold, support or cradle the articles in desired processingpositions. The receiver is also preferably constructed to otherwiseorient the semiconductor articles in substantially coaxial alignmentrelative to the axis of rotation of the rotor frame 20.

FIG. 25 shows that the base combs define a gap 64 therebetween and whichhas a given cross-sectional dimension. The individual base combs 61 and62 each have a frame portion 65 which is affixed on the surfaces 26 and37 respectively. The individual base combs further include an undulatingperipheral edge 66 having receiving grooves and interposed projections.

As best illustrated by reference to FIGS. 4 and 5, the centrifugalprocessor rotor 10 includes a pair of retainer assemblies 80. Theretainer assemblies 80 will be identified hereinafter as a firstretainer assembly 81, and a second retainer assembly 82, respectively.As will be appreciated by a study of the drawings, the first and secondretainer assemblies 81, and 82 are substantially mirror images of eachother, and therefore the features of only one of the retainer assemblieswill described in detail hereinafter. Each retainer assembly 80 includesa pair of end pieces 83. The end pieces are identified as a first orforward end piece 84, and a second or rearward end piece 85. The firstend piece 84 has a main body 90 which has a first end 91, and anopposite second end 92. The main body is further defined by an interiorfacing surface 93, and an opposite, exterior facing surface 94. The mainbody 90 also has a substantially linear portion 95, and a curved portion96.

As illustrated in FIG. 24, the main body 90 is substantially curvilinearin its overall shape. A centrally disposed aperture 97 is formed in thelinear portion 95. Further, an engagement member 100 extends normallyoutwardly relative to the exterior facing surface 94. A biasing memberor spring 102 is borne by the rotor frame 20. The spring has a main body103, with a first end 104 which is fixed by a conventional fastener onthe rear surface 26 of the front portion 21; and a second end 105, whichis fixed in a predetermined location on the linear portion 95 of themain body 90. The operation of the biasing member or spring 102 will bediscussed in greater detail hereinafter. As will be recognized, from astudy of FIGS. 3 and 4, the main body 90 is mounted for rotationalmovement about a front pin (not shown) and which is received in theindividual mounting apertures 24. The mounting pin is further in matingrelationship and received in the aperture 97.

FIG. 25 illustrates that the second end piece 85, of the respectiveretainer assemblies 80, has a main body 110 which includes a first end111, and an opposite, second end 112. The main body 110 further isdefined by an interior facing surface 113; an opposite, exterior facingsurface 114; a linear portion 115; and a curved portion 116 which ispositioned at the first end 111 thereof A centrally disposed aperture117 is formed in the linear portion 115. A rear pin 120 is received inmating relation in the aperture 34. The rear pin 120 is also received inthe central aperture 117 thereby rendering the main body 110 rotatableabout the rear pin 120.

Fastened on the first end 91 and 111 of the first and second end pieces84 and 85 respectively, is a first longitudinally disposed member 121.Further, fixed on the second end 92 and 112 of the first and second endpieces 84 and 85, respectively is a second, longitudinally disposedmember 122. The first and second longitudinally disposed members 121,and 122 are suitably oriented, such as in the fixed substantiallyparallel spaced relationship shown. These members are also furtheroriented in substantially parallel relationship to the axis of rotationof the rotor frame 20.

The first longitudinally disposed member 121 includes an inside facingperipheral edge 123 which is coated with a material that does not harmor contaminate the semiconductor articles which are being processed.

The respective retainer assemblies 80 move along predetermined paths oftravel 130 between a first, or open position 131 (FIG. 23), and asecond, or closed position 132 (FIG. 26). As will be recognized by astudy of FIG. 27, the respective retainer assemblies 80, when disposedin the second position 132, secure the individual semiconductor articleson the object receiving assembly 63 for centrifugal processing. Further,it should be understood that when the individual retainer assemblies 80are positioned in the second position 132 (FIG. 27), the secondlongitudinally disposed members 122 are operable, under the influence ofcentrifugal force imparted to the respective longitudinally disposedmembers 122 by the rotation of the rotor frame 20, to exert radiallyinward forces on the semiconductor articles thereby securing them insubstantially coaxial alignment relative to the rotor frame 20.

The centrifugal processor rotor 10 of the present invention works incombination with a transfer implement which is designated generally bythe numeral 140 in FIG. 22. The transfer implement 140 includes a faceplate 141 which is releasably secured on the distal end 17 of the arm16. The face plate has a main body 142 which is defined by a leftportion 143; a right portion 144; and bridging portions 145 whichconnect the left and right portions 143 and 144 together. Further, theface plate 141 includes an inside facing surface 150, and an outsidefacing surface 151. The outside facing surface is releasably secured injuxtaposed relation relative to the distal end 17 of the robotic arm 16.

A pair of apertures, 152 are individually formed in the face place 141.In this embodiment, the individual apertures have a first end 153; andan opposite, second end 154. The respective apertures further have avertically oriented portion 155, and a substantially horizontallyoriented portion 156. As best seen by reference to FIG. 24, theindividual apertures 152 are substantially curvilinear in shape.

The transfer implement 140 includes a pair of arms 160 which extendsubstantially normally, outwardly relative to the inside facing surface150 of the main body 142. In this regard, each of the arms includes afirst arm 161, and a second arm 162 of substantially identicaldimensions. Each of the arms 161 and 162 has a generally upwardlyoriented surface which has a number of repeating undulations or grooves163 formed therein. The upwardly facing surface may be coated or treatedwith a material which protects and does not substantially contaminatethe semiconductor articles while being transported.

As best seen by reference to FIGS. 2 and 7, a gap 164 is defined betweenthe first and second arms 161, and 162. It should be recognized that thegap 164 is larger than the gap 64 which is defined between the first andsecond base combs 61 and 62 respectively.

The transfer implement 140 is moveable along a given course of travel170. The course of travel comprises a first component 171, (FIG. 24); asecond component 172 (FIGS. 5 and 6); and a third component 173 (FIG.27). The first and third components 171, and 173, are substantiallyparallel to each other, and the second component 172 is substantiallytransversely disposed relative to the first and second components. Aswill be recognized, the transfer implement 140, while traveling alongthe first course of travel 171, cooperates with the individualengagement members 100 at the end of the first course. Continuedmovement of the transfer implement 140 along the second component 172,imparts force to the retainer assemblies, thereby effectively urging theretainer assemblies along their respective paths of travel 130, from thefirst position 131, to the second position 132. Further, the movement ofthe transfer implement 140 along the second course 172 brings thesemiconductor articles, here illustrated as a plurality of siliconwafers 180 into resting relation onto the object receiving assembly 63.

FIG. 24 shows that the transfer implement carries the individual wafersor other articles in spaced, substantially parallel relation in a batcharray.

The transfer implement 140 while moving along the first course of travel171 cooperates with the respective engagement members 100 by receivingthe respective engagement members in the individual apertures 152. Asseen in FIG. 25, when the transfer implement 140 is located at the endof the first course 171, and at the beginning of the second course 172,the respective engagement members are located at the first end 153 ofthe individual apertures 152. As best understood by a comparison ofFIGS. 5 and 6, movement of the transfer implement 141 along the secondcourse 172 has the effect of urging the individual engagement membersalong the sides of the respective apertures 152, from the first end 153,to the second end 154 thereof. This movement of the engagement members100 along the individual apertures 152 draws the engagement members 100generally radially inwardly, thereby defining the paths of travel 130which are substantially arcuate in shape (FIG. 23). It is alsonoteworthy that the apertures 152 are shaped to allow installation overthe engagement members 100 for the entire range of positions which theengagement members can assume.

The article or object receiving assembly 63 carries or cradles theindividual silicon wafers 180 in substantially the same orientation asthe transfer implement 140. FIG. 27 shows that the object receivingassembly 63 passes through the gap 164 which is defined between thefirst and second arms 161 and 162 as the transfer implement 164 movesalong the second course of travel 172. Once the plurality of wafers 180are disposed in rested relation on the article receiving assembly 63,the transfer implement 140 moves along the third course of travel 173out of the cavity 43. As will be seen by a study of FIG. 27, themovement of the individual retainer assemblies 80 along the paths oftravel 130 between the first position 131 and second the position 132orients the first longitudinally disposed members 121 in tangential,force engaging relation relative to the peripheral edge 181 of wafers180. This effectively secures the individual wafers in substantiallycoaxial alignment relative to the axis of rotation of the rotor frame20.

Upon rotation of the rotor frame 20, the second longitudinally disposedmember 122 is acted upon by centrifugal force thereby further urging thefirst longitudinally member 121 into increased radially inward forcetransmitting relation relative to the wafers 180.

In addition to the centrifugal biasing which occurs, the biasing member102 is a spring or other member which operates when the retainerassemblies 80 are in their first, or open position 131 to bias and urgethe retainer assemblies 80. The retainers are biased in the direction ofthe first position 131, and in the direction of the second position 132.This accomplishes the desired conditions of either being held in theopened or closed retainer positions.

To remove the individual wafers 180 from the rotor frame 20, the reverseof the process outlined above would be followed. In particular, thetransfer implement 140 would move along the third course of travel 173into the cavity 43. At the end of the third course of travel 173, theengagement members 100 would be received in the apertures 152, andoriented at the second end 154 thereof. The transfer implement 140 wouldthen travel along the second course of travel 172, in the direction ofthe first course 171. This movement of the transfer implement 140effectively moves the engagement members along the path of travel 130,from the second position 132, to the first position 131. As will berecognized, this movement causes the longitudinally disposed members 121to move out of tangential force engaging relation relative to wafers180.

At the end of the second course, the engagement members 100 are orientedat the first end 153 of the respective apertures. Further, as thetransfer implement 140 moves along the second course 172, the individualarms 160 engage, and cradle the wafers 180 thereby lifting them out ofengagement with the article receiving assembly 63. The transferimplement then moves along the first course of travel 171 out of thecavity 43 and on to another work station.

Operational Description of First Rotor and Transfer Implement

The operation of the preferred embodiment of the present invention isbelieved to be readily apparent but is briefly summarized at this point.

The centrifugal processor rotor 10 is best seen by a reference to FIG.23. The centrifugal processor rotor 10 for treating semiconductorarticles, such as silicon wafers 180, includes a rotor frame 20 defininga cavity 43. A retainer assembly 80 is borne by the rotor frame 20 andpositioned in the cavity 43. The retainer assembly 80 is moveable alonga path of travel 130 from a first, open position 131, to a second closedposition 132. An object receiving assembly 63 is borne by the rotorframe 20 and positioned in a given location in the cavity 43. The objectreceiving assembly 63 supports the semiconductor articles in the cavity43 for centrifugal processing.

Still another aspect of the present invention includes a centrifugalprocessor rotor 10 for treating semiconductor wafers 180 comprising arotor frame 20 defining a cavity 43 and having a predetermined axis ofrotation. A pair of retainer assemblies 80 are borne by the rotor frame.Each retainer assembly 80 is rotatable about a given axis, and has atleast one member 121 which moves along a given path of travel 130 from afirst position 131 to a second position 132. An object receivingassembly 63 is borne by the rotor frame 20 and is located in the cavity43. The object receiving assembly positions the semiconductor wafers 180in substantially coaxial alignment relative to the axis of rotation ofthe rotor frame 20. A transfer implement 140 is moveable along a courseof travel 170 into, and out of, the cavity 43. The transfer implement140 supports the plurality of silicon wafers 180 in a predeterminedorientation. Upon movement of the transfer implement 140 along thecourse of travel 170, the transfer implement 140 cooperates with theretainer assemblies 80, and further movement of the transfer implement140 along the course of travel 170 following mating cooperation with theretainer assemblies 80, carries the semiconductor wafers 180 intoresting relation onto the object receiving assembly 63. This movement ofthe transfer implement 140 along the course of travel 170 simultaneouslyurges the longitudinally disposed members 121 of the respective retainerassemblies 80 along their individual paths of travel 130 from the firstposition 131, to the second position 132.

Still a further aspect of the present invention includes a method forcentrifugally treating a plurality of semiconductor wafers 180. Themethod for treating semiconductor wafers 180 comprises providing a rotorframe 20 which defines a cavity 43; providing a movable retainerassembly 80 which is borne by the rotor frame 20, and which moves alonga given path of travel 130; providing an object receiving assembly 63which is borne by the rotor frame 43; providing a transfer implement 140which is moveable along a given course of travel 170, and which carriesthe plurality of silicon wafers 180 in a predetermined orientation intothe cavity 43; urging the transfer implement 140 along the course oftravel 170, the transfer implement 140 while moving along the course oftravel 170 cooperating with the retainer assembly 80, and effectivelyimparting force to the retainer assembly 80 to urge the retainerassembly 80 along its respective path of travel 130, whilesimultaneously carrying the individual wafers 180 into rested relationonto the object receiving assembly 63. The retainer assembly 80 securesthe individual semiconductor wafers 180 in fixed substantially coaxialorientation relative to the rotor frame 20. The method further includesthe step of imparting rotational movement to the rotor frame 20 therebycreating centrifugal force which acts upon the respective semiconductorwafers 180 by means of the retainer assembly 80.

Therefore, the centrifugal processor rotor 10 of the present inventionprovides a convenient means by which semiconductor articles, such as aplurality of semiconductor wafers 180, can be centrifugally processed ina manner which avoids the shortcomings identified with the prior artpractices and other devices.

Description of Second Rotor and Transfer Implement Assembly

FIGS. 8-11 show a further preferred rotor and transfer implementcombination according to this invention. This combination includes arotor assembly 310 which bears similarity to rotor 10 described above.Parts which are common to both rotor constructions and transferimplement constructions are similarly numbered with regard to the secondembodiment using numbers in the 300's and 400's in lieu of numbersranging from 10 up into the 100's. Corresponding parts withcorresponding reference numbers are determined by adding 300 to thefirst embodiment reference numbers. Not all features have been numberedin both embodiments to simplify and clarify the illustrations.Description of the common features of both embodiments will not berepeated. Additional description is provided below in connection withchanged or noteworthy aspects of the second embodiment.

FIG. 28 shows the robotic transfer device 15 having first, second, andthird arm portions 501, 502 and 503, respectively; which can also bethought of as upper arm 501, forearm 502 and hand 503. The secondembodiment engagement implement 440 is mounted at the distal end of themechanical arm assembly 15.

The transfer implement has cantilevered arm members 460 which extendfrom the face plate 441. The upper and inward surfaces of the armmembers have array support features in the form of grooves 463 (FIG. 31)and intervening ridges or projections which act to space the wafers 180into the spaced parallel batch array.

The face plate also serves as a retainer actuator in the form of twoapertures 452 which are appropriately shaped to provide camming orsimilar displacement action when the implement is engaged and movedrelative to lever arms 521. Lever arms 521 are pivotally mounted in thefront rotor plate 321.

Apertures 452 form part of an article retainer operator which functionsto pivot lever arms 521. FIG. 29 shows how the lever arms can be pivotedbetween upper or retracted open positions shown in solid lines, andlower or contracted closed positions shown in phantom lines. This isaccomplished by lowering the transfer implement downwardly from theupper or loading and unloading position shown in FIG. 30 to a loweredretracted position shown by phantom lines 531 in FIG. 30. To function inthis capacity the retainer operator apertures 452 are positioned overthe lever arm end extensions 522. The transfer implement is then raisedto move the lever arms up and into the open positions. The transferimplement is lowered to move the lever arms down and into extended orclosed positions.

FIG. 28 further illustrates that the transfer implement 440 can be usedto mount a visual sensing subsystem 600. Visual sensing subsystem 600 isadvantageously used to monitor the position of the transfer implement,and to monitor the condition of the rotor. The visual sensing subsystemutilizes a television camera or similar image detection device 601.Image detector 601 can be a charge coupled device image detector similarto video cameras or other suitable sensors. The image detector 601 has alight gathering lens 602 which collects light beamed toward the lensover a viewing range which is only partially suggested by view lines 605shown in FIG. 28. The lens 602 is positioned adjacent to a viewingopening 611 (FIG. 30) formed in the transfer implement face plate 441.The image detector 601 is advantageously mounted to the face plate 441using a camera mounting bracket 613 which is adjustably secured theretousing suitable fasteners 614 which are received through slotted mountingapertures 615 which allow vertical adjustment. The camera canalternatively be mounted directly upon the robot or at other suitablelocations using a variety of adjustable mounts. The output signals fromthe image detector 601 are communicated via a suitable signal cable 620or other suitable image conveying conduit.

The image information from camera 601 is communicated to a computerwhich serves as the central control processor. The image information isutilized with supporting image analysis computer software which allowsitems of the machinery to be recognized and used to verify properoperating conditions. Such image analysis software is commerciallyavailable from several sources. The software is customized to recognizespecific features such as the lever arm end extensions 522, so thatverification can be had that the lever arms are retracted upwardly andare not positioned downwardly such that installation of a batch ofwafers would cause interference and breakage of the wafers as the batchis attempted to be installed within the rotor 310. Other verificationscan also be performed using the image detection subsystem, such asexplained below.

FIG. 28 shows the preferred second embodiment rotor 310 in sideelevational detail. The front and back rotor parts 321 and 330 arejoined by several longitudinal rotor frame members 340 which are spacedabout the rotor at suitable radial positions. This provides an annularrotor frame or framework 320.

The front part 321 of the rotor frame is provided with a receivingopening 323. The receiving opening allows a batch of wafers to beinstalled within the rotor. In the preferred version shown the wafers180 are not supported upon any carrier or other array supporting pieceor pieces which stay in the processing chamber. Instead the wafer batcharray is installed into the processing chamber in an array formationdefined by the transfer implement, and then transferred to a receiverwhich is on the rotor.

The receiver is generally referred to by the reference number 363. Thereceiver advantageously includes a receiving space or cavity 343adjacent the receiving opening 323. In the preferred construction shown,the receiving cavity is substantially encompassed along the sides andrear end within the rotor frame 320. The rotor frame is left withnumerous open spaces to allow fluid access to the batch array of waferswhen held in the receiver.

The receiver assembly also preferably includes one or more receiverarray supports 350. As shown, array supports 350 are provided in theform of combs having receiving grooves and intervening ridges orprojections. The edges of wafers are captured in the receiving groovesand spacing between adjacent wafers is maintained by the interveningprojections. The receiver 363 includes four stationary supports 350 eachbeing fitted with the support combs which directly contact the edges ofthe wafers.

The front piece 321 of the rotor frame includes the receiver opening323. The receiver opening is preferably provided with cutouts 563 whichallow sufficient clearance for the transfer implement to move downwardlyand transfer the edges of the wafers into supporting contact with thesupports 350. Sufficient clearance is also provided to allow thetransfer implement to move downwardly to allow free travel clearancebetween the transfer implement supports on arms 460 and the adjacentportions of the wafers resting in the receiver supports 350. Thisdownward transfer and clearance is illustrated in FIG. 30.

The rotor assembly 310 further includes a complementary pair of retainerassemblies 380. The retainers 380 each include a longitudinal mainretainer member 390 which is mounted for pivotal action by front andback retainer end pieces 384 and 385. The front and back end piecesextend through apertures formed in the adjacent rotor frame pieces 321and 330, respectively. Bushings or other suitable bearings 386 areprovided to improve pivotal support. The front end pieces 384 areconnected to the lever arms 521. Lever arms 521 and end extensions 522serve as part of the retainer operators used to operate the retainersbetween open and closed positions.

The rear end pieces 385 are connected to a rear lever arm 596. The rearlever arm has a ball (not shown) mounted at the distal end thereof. Theball engages with either or two detents (not shown) formed along therear face of the rear rotor part 330. This construction provides arestraint which maintains the retainers in either open or closedpositions.

The retainers 380 also preferably include contacting bars which haveundulating groove and projection faces similar to the stationaryreceiver members 350. Biasing springs are not shown similar to spring102, but could be utilized to add additional biasing forces to theretainers into the open, closed or both positions.

The retainers 380 are preferably constructed so as provide automaticcentrifugal motivation which urges the retainers into a closed positionto engage and securely hold wafers or other articles being processed.This is preferably done by providing appropriate balance to the mainretainer member 390 relative to the pivotal mounts at each end. When therotor rotates the center of gravity of the retainer assemblies causesthe retainer support members to pivot into a closed position wherein thesupport members are extending inward in a nearly radial orientationtoward the rotational axis. It is even further preferred that thecentrifugal forces and balance of the assemblies be designed to pivotthe retainers slightly past a radial line in order to more securely holdthe retainers in a closed position and keep it affirmatively in thatposition using the detent construction and mechanical engagement betweenthe retainers and the wafers or other articles being retained in therotor.

Operational Description of Second Rotor and Transfer Implement

The processing system preferably operates using certain methods forcentrifugally processing batches of semiconductor articles, such as theillustrated wafers 180. The novel methods can according to one aspect ofthis invention involve supporting plural semiconductor articles in abatch array upon a suitable transfer implement, such as the transferimplements 140 and 440 described herein. The batch of articles typicallyare relatively thin wafer shaped articles which can be circular disks orpanels having other possible shapes. The supporting advantageouslyinvolves arranging the articles in a spaced parallel relationship toform the batch processing array. The articles are preferably spacedapproximately equal amounts, although irregular spacings may bear someadvantage in particular circumstances. The articles can be supportedupon peripheral edges thereof to form the array. The supporting step ispreferably done by inserting the peripheral edges of the articles withingrooves or receptacles formed along supporting surfaces of the transferimplement, such as at grooves 163 or 463. The supporting can also bedefined to include abutting the marginal portions of the wafers or otherarticles against the intervening projections formed between the groovesto provide endwise support against displacement in the longitudinaldirections.

The novel methods can in another aspect of the invention include movingthe transfer implement and supported batch array to and into aprocessing station, such as processing stations 19, which are adapted toreceive and support the batch array which is formed without a carrierwhich remains in with the wafers throughout centrifugal processing. Themoving step or steps include moving the batch array on the implement tothe processing station and aligning the batch array with a processingvessel main opening, such as opening 203 (FIG. 31). The aligningoperation occurs by positioning and orienting the array on the implementso as to be approximately aligned with the receiver formed on the rotor,such as receiver 463 on rotor 310.

The moving step can additionally be defined by inserting the batch arrayof articles through the main opening of the processing vessel. Suchinserting step can be accomplished by positioning the transfer implementand supported batch array within the receiver, such as receiver 463.

In order to minimize potential damage to the wafer or other articlesheld in the batch array, it is preferable to include a retainer openpositioning step which causes positioning of the movable articleretainers, such as retainers 81 and 82, into retracted or openpositions. In the retracted open positions the retainers are laterallywithdrawn away from the receiver opening to allow clear access forinsertion of the batch array and supporting transfer implement inthrough the receiver opening and into longitudinally aligned orappropriate stopping position within the receiver. The opening orpositioning of the retainers is advantageously accomplished at the endof the prior cycle of processing when the transfer implement is movedupwardly, thus engaging the retainer actuators in the form ofreceptacles 152 with the ends of the retainers to effect a liftingoperation of the retainers. This lifting causes the retainers to beactuated and repositioned into the open positions.

During the loading of the receiver, the methods further preferablyinclude the step of engaging the batch array with the receiver tosupport the plural semiconductor articles using the receiver in a batcharray upon the supporting features of the receiver. This isadvantageously accomplished by lowering the transfer implement asindicated in FIG. 30 in phantom lines 531. The step of lowering orotherwise displacing the transfer implement and supported waferslaterally with respect to the longitudinal axis of the array and axis ofrotation, causes a transferring to occur. This transferring results intransfer of the wafers from the transfer implement onto supportingsurfaces and features of the batch receiver. This transferring ispreferably done in a manner which involves longitudinally aligningcorresponding grooves which are on the transfer implement with receivinggrooves in the article receiver. This results in the individualsemiconductor articles being supported in a manner the same orsubstantially similar to the supporting step described above inconnection with supporting the articles in a batch array on the transferimplement, as explained above.

In another aspect the novel methods preferably include repositioning orotherwise moving at least one movable article retainer into a closedposition. This effects a retainer closing operation. In such closingoperation and associated closed position, the article retainer orretainers are in juxtaposition with the plural semiconductor articlesheld in the receiver. More preferably, the article retainers are indirect physical contact with the semiconductor articles, such as alongperipheral edge surfaces thereof. The article retainer or retainers arerepositioned in a retainer close positioning step. This retainer closepositioning step is performed using the preferred embodiments shown, asa simultaneous operation or actuation associated with the engaging stepdescribed above, although simultaneous actuation may not be needed insome forms of the invention. This closing is effected in a manner whichis the complement of the retainer opening operation or open positioningstep described above.

The methods further include retracting or withdrawing the transferimplement from the processing chamber. This is advantageously done usingthe robotic transfer 15 and moving the transfer implement outwardlyalong a line of travel which is in the same approximate orientation asthe travel into the processing chamber.

In the close positioning step the transfer implement moves downwardly orotherwise in a laterally displacing mode of action. This causes force tobe transferred between the transfer implement retainer actuatoropenings, such as openings 152 and 452, against the exposed ends or theretainer mechanisms (100 and 522), bringing about movement of theretainers 81, 82 and 381, 382 into the closed positions. In these closedpositions the contacting surfaces of the retainers may either beslightly spaced or brought in direct physical engagement with thearticles being processed so as to effect an initial or preliminaryurging or biasing which involves forcing of the semiconductor articles.This preliminary forcing or urging helps to seat the articles within thereceiver grooves and minimizes the chance of vibration or movement ofthe articles, particularly as the rotor increases in angular speed. Suchmovement can be problematic in some processing operations, and is moregenerally undesirable.

In other aspects of the invention, the methods further include closingthe processing chamber opening using a movable processing chamber doorto provide a substantially enclosed processing chamber. In theembodiment shown in FIG. 31 this is accomplished by moving theprocessing chamber door 202 upwardly and across the opening 203. Otherconfigurations are alternatively possible.

The methods further include rotating the rotor and supported wafers orother semiconductor articles. The rotating step is preferably performedto provide better access to processing fluids supplied to the processingchamber. The supply of processing fluids can occur in the form ofliquids sprayed into the processing chamber, or gases which are emittedinto the processing chamber. The rotating action is further usefulwithout fluid application to spin liquids from the surfaces of thearticles being processed, and to aid in drying liquids from the exposedsurfaces of the wafers. The centrifugal action provides improved gaseouscontact to aid in drying or other gaseous processing phases.

The novel methods further include maintaining or biasing the articlesinto their desired processing positions during centrifugal processing.This is advantageously accomplished by providing automatic centrifugalbiasing action using the article retainer operators. The articleretainer operators respond to centrifugal forces developed duringrotation of the rotor. The retainer operators preferably have arestraining means, such as the biasing spring member 102 or the detentrestraint which help to lock the restraints into the closed positionduring rotation. The restraining action can also be accentuated bydesigning the balancing of the retainer operators such that thecontacting surfaces of the retainers go past a radial orientation whichis pointing directly at the central axis of rotation and positions theretainer operators beyond this point to produce an action whichmaintains the retainers in a fully closed position until they areaffirmatively released by the retainer actuator provided in the form ofthe transfer implement and its opening operation described above.

The methods can also further include opening the processing chamberopening by retracting the movable processing chamber door. This is donein a manner complementary to the door closing step listed above.

The novel methods also preferably include verifying retainer positionsbefore any insertion of the transfer implement is attempted. This helpsto reduce the risk of possible damage to the machine or articles beingprocessed. The verifying can be performed in anticipation of theunloading phase of the processing. Verifying can best be accomplishedusing the image sensor 601 which looks at the open processing chamberand recognizes either or both the lever arms 521 and ends 522 usingimage analysis software which is commercially available. If the leverarms are in a closed position, then it is appropriate for the transferimplement to proceed with insertion to progress in unloading themachine.

Verifying steps can also be used prior to unloading to verify that theretainer actuator lever arms are in the desired closed positions.Additional verifying can be performed after loading the articles intothe rotor, to assure that the retainers are in closed positions beforespinning the articles.

The novel methods also preferably include inserting an unloaded transferimplement into the processing chamber to unload the batch array from therotor. The inserting step is best prefaced with a set of moving andrelated steps explained above in connection with the transfer implementwhen loaded with a batch of articles. In the case of inserting andmoving the unloaded transfer implement the arms 140 and 160 are insertedin a complementary relationship avoiding the receiver supports 63 and463. The transfer implement is brought into the receiver opening in arelatively low condition associated with insertion to load andretraction after loading the wafers onto the rotor article receiver. Thesteps further include longitudinally aligning or stopping the transferimplement in a desired position in anticipation of lifting andtransferring the articles onto the transfer implement. The axialaligning step brings corresponding grooves of the article supports intoregistration.

The novel methods in another aspect include lifting or otherwiselaterally displacing the transfer implement to cause an engaging of thearticles supported on the receiver article supports. This effects atransferring and brings the transfer implement into a supporting actionfor the articles.

The lateral displacing action of the transfer implement also preferablycauses a simultaneous actuation of the article retainers on the rotor.This releases the wafers or other articles and allows upward or otherappropriate lateral displacement so that the wafers are brought into aretractable orientation and position for removal of the articles fromthe processing station.

The methods also in another aspect include retracting the transferimplement and supported batch array of articles from the processingstation.

In further aspects the retracted batch array can then be prepared andcontrolled for repeating some or all of the above processing steps at asecond or subsequent processing station as the particular requirementsmay be.

Control System

FIG. 32 shows a preferred control system used in processor 11. Thecontrol system advantageously uses a modular design which incorporatecommercially available computer modules, such as Intel 80486 orequivalent based computer or computer boards, to perform variousfunctions. FIG. 32 shows the human operator interaction station 704 Thefirst such station 704 has an associated control processor 1341 ofconventional design and an electrically attached display and controlpanel 705. Control and display panel 704 is accessible from the front orclean room side of processor 11. Additional control stations canalternatively be provided at central processing control rooms, at thegrey room side of the processing system, or at other desired locationsand connected to added input ports 1360.

Control stations are connected using a standard network interface hub1350. Network hub 1350 is connected to a central controller, such as acomputer file server 1351. Hub 1350 can also be used to connect anoutside control or monitoring station at ports 1360 for additionalcontrol capabilities, data acquisition, or monitoring of processing andcontrol functions.

Hub 1350 is further connected to processor control modules 1361-1363,which are also conventional computers without displays. Three processorstation control modules 1361-1363 are each associated with processingstations 19 respectively. Similar, added modules are used as needed forthe particular number and types of stations 19 used in system 11. Thesestation control modules allow independent processing routines to be runat the processing stations and for data to be recorded indicating theprocessing performed in each particular batch being run by eachprocessing station.

Processing station control modules are connected to and interact withthe processing station motors, plumbing, etc which are collectivelyidentified with the processing station number 19 in FIG. 32.

FIG. 32 further shows an interface subsystem controller 1381, whichagain is a computer. Interface subsystem controller 381 is electricallyconnected to various features of the interface subsystem to both controloperation and receive confirmatory signals of movements and positions.The interface controller 381 is preferably connected to the interfacesection to receive signals through a number of optical fibers 1386 usedto convey signals from positional encoders for the first and secondcarriages 1382, limit switches 1383 which detect the limit of travel ofthe carriages and elevators, and wafer detectors 1384 which detect wafercarriers and wafers held in the interface section. The system ispreferably constructed so that most or all sensed signals used in thecontrol and operation of the interface are communicated by optical fiberto eliminate the risk of cross-talk between signal lines. The opticalfiber transmitted signals are converted into electronic signals by anoptical fiber signal converter 1387 which produces electronic signalswhich are communicated to computer 1381.

FIG. 32 still further shows a conveyor control module in the form of acomputer 1391 without display which is electrically connected to variousparts of the conveyor, such as the mechanical arm drive motors 1256,1271 and 1301, encoder 1220, and other components thereof notspecifically illustrated.

The conveyor control module also preferably receives a number of signalsthrough optical fibers 1396. Optical fibers 1396 are used to conveysignals from angular position encoders and motor encoders for theconveyor 15 which are for simplicity exemplified by encoder 1220 in FIG.32. Limit switches for the conveyor are exemplified by limit switch 1278in FIG. 32. Hall effect sensors 1395 are used in sensing operation ofthe motors of the conveyor. The system is preferably constructed so thatall sensed signals used in the control and operation of the conveyor arecommunicated by optical fiber to eliminate the risk of cross-talkbetween signal lines and provide a smaller cable bundle which is movedin connection with tram motion up and down the track. The optical fibertransmitted signals are converted into electronic signals by an opticalfiber signal converter 1397 which is connected to reconvey the signalsto computer 1391.

FIG. 33 Processor Generally

FIG. 33 shows a preferred processing system 1040 according to thisinvention. Processing system 1040 includes a basic frame 1041 whichprovides structural support for related components. Processor 1040 hastwo fundamental sections, one of which is the interface section 1043.The other fundamental section is the processing section 1044.

The frame supports an enclosure envelope 1045 which in FIG. 33 is shownpartially removed adjacent the processing section for purposes ofillustration. The enclosure envelope encloses a working space 1046within portions of processor 1040. Wafers 1050 are held and maneuveredwithin the enclosed working space. The wafers are moved between multipleprocessing stations 1071-1073 contained within the processing section1044. The working space can be supplied with a purge gas and operated ateither slightly elevated or slightly reduced pressures relative toambient atmospheric pressure.

The upper portions of processor 1040 are provided with an interfacefilter section 1038 and a processing filter section 1039. These filtersections preferably employ HEPA type ultrafiltration filters. Air movingequipment forces air through the filters and downwardly into the workingspace to move contaminants downwardly and out through the back side ofthe processor.

The multi-station processor 1040 also preferably has a process stationmaintenance section 1053 which is separated from the work space 1026 byportions of the enclosure envelope 1045. Processor 1040 also preferablyhas an instrumentation and control section 1054 mounted rearwardly fromthe interface section 1043. Control section 1054 preferably includesvarious control equipment used in processor 1040.

Maintenance section 1053 and control section 1054 are of potentiallyhigher contamination levels due to the presence of various equipmentcomponents associated with the processing stations. The processor 1040is advantageously mounted in a wafer fabrication facility with cleanroom access to the front of the processor along front panel 1048. Themaintenance and control sections are preferably accessed from the rearof processor 1040 through a gray room adjacent the clean room. Such grayrooms have fewer precautions against contamination than the clean room.This configuration reduces plant costs while allowing access to portionsof the processor more typically needing maintenance.

The front of processor 1040 includes a front control panel 1057 allowingoperator control from the clean room. Control panel 1057 isadvantageously a touch screen cathode ray tube control display allowingfinger contact to the display screen to effect various controlfunctions. Control section 1054 also preferably includes a secondarycontrol panel which faces rearwardly into the gray room so thatoperation can be affected from either front or back of the machine. Allcontrol functions and options are displayed upon the control panels toeffect operation and set up of the processor.

As shown, wafers 1050 are supplied to and removed from the enclosed workspace 1046 of processor 1040 using interface section 1043. Wafers aresupplied to the interface section in industry standard wafer carriers1051 (detailed in FIG. 37). The wafer carriers are preferably suppliedin groups, such as a group of four carriers. The groups are placed upona cantilevered shelf 2101 forming a part of a first carriage 2100. Shelf2101 extends through an interface port 1056 which is controllably openedand closed using a interface port door 1059. Adjacent the interface portand control panel is a view window 1058 through which a human operatorcan see operation of processor 1040. FIG. 33 shows two wafer carriers1051 positioned upon the cantilevered shelf 2101. There are twoadditional positions available for two additional carriers which areleft unloaded in FIG. 33.

Wafer Tray

Refer to FIGS. 34 and 35 which show the novel wafer tray 1060 in greaterdetail. Wafer tray 1060 includes an upper surface 1061 and a lowersurface 1062. The tray also has a first end 1063 and a second end 1064.Sides 1065 extend between the first and second ends. Additional featuresof the tray surfaces will now be more fully detailed.

Upper surface 1061 has a series of wafer tray receivers 1066. Wafer trayreceivers 1066 each comprise a semicircular groove or channel havingdownwardly converging receiver sides 1067. The converging receiver sides1067 adjoin to a receiver bottom section 1068 which is a relativelynarrow slot having substantially parallel slot walls. The slot sectionis sized to provide a width about 0-10% greater than the thickness ofthe wafers which are being received therein. The receiver bottom or slotsection has bottom surfaces 1069. The lower portions of the slotsections 1068 are formed so as to be intermittently closed at slotbottom surfaces 1069 and open along receiver drain apertures 1070 (FIG.35). The slot bottom surfaces 1069 exist along longitudinal foundationbars 1075 and side rail portions 1076. The particular number of wafertray receivers 1066 in any particular tray 1060 is variable. Typically,there will be 25 or 50 wafer receivers in order to correspond with thecapacity of associated wafer carriers 1051 being used in other parts ofthe fabrication plant.

The upper surfaces of wafer tray 1060 also preferably include side landportions 1079. The side land portions are formed to reduce overallheight of the tray while maintaining the general semicircular receivershape. The overall width of tray 1060 is appropriately sized so thatmore than approximately 50° of arc are seated, more preferablyapproximately 60°-80° of arc are encompassed for seating the wafers inreceivers 1066. Even more preferably the arc of the receiving channelsis approximately 65°.

The wafer tray ends 1063 and 1064 are preferably planar andperpendicular relative to a longitudinal axis 1080 (FIG. 36) whichextends perpendicular to the receiving grooves along the center point ofthe receiving groove arcs defined by bottom surfaces 1069. Longitudinalaxis 1080 also coincides with the centers of the wafers 1050 supportedon the wafer tray. Tray ends 1063 and 1064 are advantageously providedwith apertures 1088 for receiving a tool therein to allow handling ofthe trays with minimum contact, such as during cleaning.

Wafer tray 1060 has side rails 1076 which extend along both sides. Theside rails have outer side surfaces 1065 which are advantageously formedto provide tray support features 1080. As shown, tray support features1080 include a tray side channel 1081. Tray side channel 1081 has adownward facing bearing surface 1082 which bears upon supporting toolsand equipment as explained more fully hereinbelow. Adjacent to surface1082, is an outwardly facing channel base surface 1083. Bearing surface1082 is preferably constructed to form an included angle ofapproximately 120° of arc relative to the channel base 1083. Channel 81further includes an upwardly facing third surface 84 which serves tocomplete the channel shape of the tray support features and providesincreased structural engagement between the wafer tray and equipmentwhich engages the tray using the tray side channels 81.

The lower surface 1062 of tray 1060 is preferably formed with adownwardly facing contact or foot surface 1086. As shown, foot surface1086 defines a footprint with five longitudinal segments associated withside rails 1076, longitudinal bars 1075, and end panels 1063 and 1064.The lower surface of the tray also is preferably constructed to havelongitudinal base recesses 1077 between bars 1075 and side rails 1076.Processing fluids drain from the wafers 1050 and wafer tray 1060 throughthe receiving slot openings 1070 and base recesses 1077.

The novel wafer trays 1060 provide improved processing of wafers inprocessor 1040. The improvements include improved access of processingfluids to the surfaces of wafers 1050. The improved access of processingfluids occurs because there is less coverage of the wafers as comparedto prior art carriers 1051. Only relatively small marginal edge portionsalong the arc of the receivers is covered. Thus allowing almost fullaccess to the faces of the wafers by processing fluids. The improvedaccess to processing fluids in turn results in reduced processing timesand greater uniformity and effectiveness of the processes upon thesurfaces being treated. Wafer tray 1060 also results in a small combinedsize of the wafer batch within processor 1040. This translates into amuch smaller overall size of processor 1040 and reduced floor spacerequirements in clean rooms and adjacent gray rooms. Since the cost offloor space in these facilities is very high, the installed cost of theprocessing system 40 is kept relatively lower. These factors allattribute to better yields, improved quality and reduced costs ofproduction.

Standard Wafer Carrier

Processor 1040 is designed to work in conjunction with a standardindustry wafer carrier which is illustrated in FIG. 37. Such carriersare available from a number of supplying manufacturers. Carrier 1051 hasa holding trough 1034 with a series of edge receiving receptacles 1035along side walls 1036. End walls 1037 are typically provided withhandles 1038. The bottom of carrier 1051 is provided with a bottomopening (not shown) which is rectangular and defined between base rails1039. FIG. 37 shows a wafer tray 1060 positioned beneath wafer carrier1051 aligned to pass up through the bottom opening of the carrier. Wafertray 1060 is sized to pass through the bottom opening.

Interface Section

The interface section 1043 takes the wafers from the wafer carriers andinstalls them onto the specially constructed wafer trays 1060. The wafertrays provide improved processing of wafers 1050. The interface sectionalso preferably provides a holding or inventorying capability for bothwafers awaiting processing and wafers which have been processed. Thusthe interface section constructed as shown in FIG. 33 functions as bothan input subassembly, output subassembly and wafer holding station.

Interface 1043 is substantially enclosed by the enclosure envelope 1045.Interface 1043 has open work spare portions connected to the portions ofwork space 1046 contained within the processing section 1044. Theinterface includes a interface port 1056 formed through envelope 1045.Interface port 1056 allows wafers to be loaded into and removed fromprocessor 1040. Interface port 1056 is preferably provided with ainterface port closure in the form of a movable door 1059. Movable door1059 is powered and extends upwardly from below to close the port and isretracted downwardly to open the port. This construction allows theinterface port door to be automatically controlled to the extentdesired.

FIGS. 38-44 show the principal operational portions of interface 1043.These portions serve to provide a wafer transfer which transfers wafersfrom the industry standard wafer carriers 1051 and installs the wafersonto the novel wafer trays 1060. Additionally, interface 1043 serves tohold wafer batches loaded onto the trays. These loaded tray batches areheld for processing in the processor. Still further interface 1043allows for the storage of unloaded wafer trays. As shown, interface 1043also performs loading and unloading operations through interface port1056.

FIG. 38 shows that the preferred interface 1043 has a base 1099 which issecured to frame 1041. A first or lower carriage 2100 is mounted formovements, such as the preferred horizontal movement. A second or uppercarriage 2102 is also mounted for horizontal movement. Interface 1043also has four elevators 1104 which provide vertical movement.

Base 1099 in some respects acts as an extension of frame 1041 andfurther serves to separate the interface section compartment into aninterface section portion of working space 1046 and a mechanicalcompartment 1098 (FIG. 33) which is below and subjacent to the workingspace and base 1099. As shown, base 1099 is provided with four elevatoropenings 2102 which serve as apertures through which elevators 2104extend.

Base 1099 also is provided with first carriage travel openings or clefts2106. Clefts 2106 receive portions of a first carriage support pedestal2107 which extend downwardly from the first carriage beneath base 1099.The pedestal extends down to a first carriage support track (not shown)which is below base 1099 in the mechanical compartment 1098. Pedestal2107 is connected to a first carriage operator (not shown) which isadvantageously in the form of a rotatable linear screw drive operatorsimilar to the operator described below in connection with secondcarriage 2102.

FIG. 38 also shows that interface 1043 includes two carriages 2100 and2102 which are movable relative to elevators 2104. Carriages 2100 and2102 are preferably mounted for simple linear motion relative to theelevators. However, alternative configurations and movement patterns maybe possible. Carriages 2100 and 2102 are independently operable orotherwise controllable to allow different relative horizontal positionsand movements of the first and second carriages.

As shown, first carriage 2100 is positioned above base 1099 and belowthe second carriage 2102. This preferred configuration results in thefirst carriage functioning as a lower carriage, and the second carriagefunctioning as an upper carriage. Elevators 2104 serve to move waferbatches between a first or upper carriage level associated with thefirst carriage and a second or lower carriage level associated with thesecond carriage.

First carriage 2100 includes an outer or forward portion forming a firstsection 2111 of the carriage. This outward section is in the form of acantilevered shelf or carrier support projection 2101. Carrier supportprojection 2101 serves to support wafer carriers 1051 thereon. Firstcarriage 2100 is laterally movable to extend the carrier projection oroverhang through interface port 1056 into the fully extended firstcarriage receiving position illustrated in FIG. 33. The overhangingcarriage shelf 2101 is provided with carrier support features which areadvantageously in the form of carriage support ledges 2109. The carriersupport ledges are preferably recessed areas formed in the upper surfaceof shelf 2101. The carrier support features are advantageouslyconstructed to provide lateral support against unintended horizontaldisplacement in either X or Y directions (see FIG. 33). The carriersupport features also hold the carriers to prevent downward movementfrom a desired vertical or Z position, but allow vertical movement abovethe shelf for easy installation and removal of the wafer carriers.

The carrier support ledges 2109 or other carrier support features arepreferably positioned adjacent or about first carriage transfer openings2110. The support ledges are most preferably peripheral recessed areasabout the opening 2110. Openings 2110 are provided to allow extension ofthe elevators 2104 therethrough. Extension of the elevators throughopenings 2110 is used in conjunction with the transfer of wafers betweenthe wafer carriers 1051 and wafer trays 1060 in either incoming oroutgoing directions.

First carriage 2100 also preferably includes a second or central section2112 which includes a group of four first carriage pass-through openings2113. Pass-through openings 2113 extend through the deck of the firstcarriage to allow extension of the elevators therethrough. Pass-throughopenings 2113 also allow unloaded wafer trays 1060 to be passed upwardlyand downwardly through the first carriage deck in a manner as explainedmore fully below.

First carriage 2100 is further provided with a third or rearward section2113. Rearward section 2113 includes an empty or unloaded wafer traymagazine or storage 2115. The empty wafer tray storage is advantageouslyin the form of four arrays each having three receptacles to receivethree wafer trays therein. The receptacles each include shoulder pairswhich function as rests upon which the side rails 1076 of the wafertrays rest. The shoulder pairs are along arranged along opposing sidesof an empty tray gallery 2116 which is common to all three receptaclesof a single storage array 2115. Galleries 2116 allow the heads of theelevators to extend upwardly to engage empty wafer trays and lift themfor removal from the storage array. The empty tray gallery also extendsthrough the deck of the first carriage, and is contiguous with and opento the adjoining pass-through openings 2114.

The empty tray storage is also preferably provided with an empty traystorage roof panel 2117 which extends over and protects the empty wafertrays from downwardly drifting contaminating particles. The roof panelsare supported by first carriage rear section support panels 2118.

The first carriage is further advantageously provided with a secondcarriage pedestal inlet opening 2119 which allows a support pedestal ofthe second carriage to extend thereinto when the second carriage ismoved forwardly.

Interface 1043 also includes the second or upper carriage 2102. Uppercarriage 2102 has an upper carriage deck 2121 which is supported by asecond carriage support pedestal 2122. Pedestal 2122 has a linear driveoperator 2123 which is advantageously in the form of a rotatable screwdrive 2124 which moves the second carriage forwardly and backwardlybetween retracted and extended positions.

The upper carriage is provided to function as a loaded tray holding orinventorying station. As shown, this function is accomplished by havingthe second carriage in a position above the first carriage, and providedwith a series of loaded tray holders 2125. Loaded tray holders 2125 areformed as receptacle ledges formed in the deck. The receptacle ledgesare adjacent to second carriage elevator openings 2126. Openings 2126are preferably portal openings which have open entrances at the forwardends thereof. As shown, the upper carriage is configured to hold twogroups, each group having four wafer trays in a four by two loaded wafertray storage array.

Interface 1043 also includes elevators 2104 which have elevator rods orshafts 2128 and enlarged elevator heads 2129. The elevator heads areconstructed to engage the lower surface 1062 of wafer trays 1060 in astable manner. Most preferably the upper contacting face 15 of elevatorhead 2129 is provided with four engagement projections 2130 at the frontand back of the contacting face. The engagement projections are spacedand sized to fit within the longitudinal recesses 1077 of trays 1060adjacent the end panels. This provides positive engagement againstlateral displacement of the trays relative to the elevator head duringautomated handling of the wafer trays by the interface.

Interface 1043 is advantageously constructed to handle wafer carriersand wafer trays in groups or gangs of four at a time. Although thisconfiguration is preferred, it is alternatively possible to have othergang sizes.

Operation of Interface Section

The operation of interface 1043 will now be described in connection withthe series of drawings shown in FIGS. 39-44. FIG. 39 shows the interfacemoved from the fully retracted positions of FIG. 38 into an initialloading position wherein the first carriage has been extended fully toposition the overhanging carrier shelf 2101 through the interface port1056. FIG. 39 also shows the carrier shelf loaded with four wafercarriers 1051 containing wafers 1050. The carriers and wafers arepositioned in the carrier support receptacle ledges 2109 over the wafertransfer openings 2110. The second carriage 2102 is maintained in thefully retracted position.

After the wafer carriers have been loaded onto shelf 2101, the firstcarriage is retracted. When sufficiently retracted, the interface portdoor 1059 is closed by extending the door upwardly. The first carriagecontinues to retract rearwardly until the elevator head 2129 is alignedwith the stored trays held in empty wafer tray storage arrays 2115. Atthis tray pick position, the first carriage is stopped and the elevatorsare aligned below the stored wafer trays. The elevators are thenextended upwardly to engage and lift the lowest empty trays from thefour storage arrays. The elevators are then stopped and held at a traylift elevation position.

The first carriage is then retracted further to bring the passthroughopenings 2114 into alignment with the elevators and elevated empty wafertrays positioned upon the heads of the elevators. At this pass-throughposition of the first carriage, the first carriage is stopped. Theelevators 2104 are then retracted downwardly to pass the empty wafertrays through the deck of the first carriage. The empty trays are movedownwardly until they are below and clear of the first carriage.

The first carriage is then moved rearwardly from the pass-throughposition into a transfer position. In the transfer position the firstcarriage is positioned so that the elevators and empty wafer trays heldthereon are aligned with the bottom opening of the wafer carriers heldin carrier holders 2109. FIG. 41 shows the first carriage in the firstcarriage transfer position.

FIG. 41 further illustrates the transfer of wafers from the wafercarriers 1051 and their installation onto the wafer trays 1060. In FIG.41 the elevators have been extended upwardly after the first carriagehas assumed the transfer position. The transfer includes aligning theindividual wafer receivers 1066 below the wafers 1050 held in carriers1051. As the elevators extend upwardly, the tray moves up, into andthrough the open bottom of carriers 1051. The edges of the wafers 1050are guided by the V-shaped receiver mouths having downwardly convergingreceiver side surfaces 1067. The edges of wafers 1050 are guided by thereceiver mouths into the relatively close fitting receiver slots orchannels 1068. The edges of the wafers bear against the wafer slotbottom surfaces 1069. The bearing allows the wafers to further be liftedupwardly by the elevating trays 1060.

FIG. 41 shows the elevators fully extended with trays 1060 fullyelevated and with wafers 1050 held in an aligned side-by-side array uponthe trays. In this condition, interface 1043 has transferred the wafersand the loaded wafer trays are ready to be moved to the holding stationson second carriage 2102. To accomplish this, the second carriage isextended outwardly and forwardly from the retracted position into anextended position, such as the fully extended position shown in FIG. 42.In this position the second carriage has been moved forwardly so as toalign the rearward gang of loaded tray holding receptacles 2125 with theelevated wafer trays. The elevators are then retracted downwardly tolower the loaded wafer trays into the receptacles 2125. After the loadedtrays have been received in receptacles 2125, the second carriage canthen be retracted rearwardly into a retracted holding position, such asshown in FIG. 43. FIG. 43 also shows the elevators 2104 fully retractedand the first carriage retracted with empty wafer carriers 1051 awaitingdischarge from the interface section.

FIG. 44 shows the first carriage repositioned into a fully extendedcarrier unload position. This position is also the initial load positionshown in FIG. 39. The empty wafer carriers are removed using a suitablemeans, such as manual removal by a human operator (not shown). LoadedWafer are then loaded onto the overhanging shelf of the first carriageand the process illustrated by FIGS. 39-44 is repeated for a second gangor group of carriers, wafers and trays. The second loading processdiffers only slightly from the process described above. One differenceis that different trays are used from the empty tray storage magazines2115. Another difference is that the second gang of loaded trays areheld in the outer or forward holding receptacles 2125 instead of therearward tray holders used by the first gang of wafer trays.

Processing Section

The processing section 1044 of processor 1040 will now be described ingreater detail. As shown, processing section 1044 includes threecentrifugal processing stations 1071-1073. Each processing stationincludes a processing chamber bowl 2131 which substantially encloses aninternal processing chamber 2132. A centrifugal processing enclosuredoor 2134 is mounted for controlled powered vertical motion between aclosed upward position and a downwardly retracted open position.Preferred door constructions are shown in U.S. Pat. No. 5,302,120, whichis hereby incorporated by reference.

Within each processing chamber is a suitable rotor for receiving loadedwafer trays, such as rotor 2133 detailed in FIG. 50. FIG. 51 shows afront view of rotor 2133 without a wafer tray loaded therein. FIG. 54shows a front view similar to FIG. 53 with a loaded wafer traypositioned within the rotor. Rotor 2133 is specially constructed toreceive and appropriately engage wafer tray 1060 using wafer trayengagement features as explained below. The resulting interlockinginterengagement of the tray with the rotor substantially preventsdislodgement until appropriately removed.

Rotor 2133 includes three principal ring pieces 2141-2143. The frontring 2141 has a beveled rotor opening 2149. The front, central and rearrings are connected by connecting longitudinal bars 2144 and 2145. Upperlongitudinal bars 2144 are spaced from the wafer trays 1060 and areprovided with inwardly directed longitudinal bumpers 2146. Adjacent thewafer tray receptacle 2136 are three additional longitudinal bars 2145.The inward edges of bars 2145 serve to guide and support wafer trays1060 appropriately positioned within the wafer tray receptacle.

The wafer tray engagement features used in the wafer tray receptacleinclude a rotor tray receiving channel 2136. The sides of receivingchannel 2136 include rotor tray engagement projections 2137. The rotortray engagement projections are shaped and sized to complement and bereceived along the tray side channels 1081. However, the tray sidechannels are substantially higher than the engagement projects becausethe trays are loaded using a tray engagement tool 2180 which insertsbetween the downward facing bearing surface 1082 of the tray and theupward surface of rotor engagement projections 2137. Additionally, theclearance is preferably sufficient so that engagement tines 2184 canalso pass through the available space during insertion into the rotor toretrieve a tray therefrom.

The wafer tray engagement features used in rotor tray receiving channel2136 also include opposing side receiving flutes 2138. Flutes 2138receive the longitudinal side flanges 1085 of tray 1060 in relativelyclose fitting interengaging relationship. The bottom or foot surface1086 of tray 1060 bears upon inwardly directed tray support surfaces2147 on the longitudinal bars 2145. This advantageously occurs betweenboth outer support bars 2145 with both side rails 1076 of the tray, andalong a central tray support bar 2145 and the center longitudinalfoundation bar 1075 of the tray. Central longitudinal bar 2145 isadvantageously provided with a bumper bar 2148 (FIG. 51).

The processing stations are each independently driven by rotatingassembly motors 153 and have other features of a centrifugal fluidprocessor as needed for the desired processing of that station.Additional details of a preferred construction of centrifugal processorare well-known.

The specific processing performed in processing stations 1071-1073 caneach be different or of similar nature. Various liquid and gaseousprocessing steps can be used in various sequences. The processor isparticularly advantageous in allowing a series of complex processes tobe run serially in different processing chambers set up for verydifferent chemical processing solutions. All the processing can beaccomplished without human handling and in a highly controlled workingspace, thus reducing contamination and human operator handling time.

The processing section 1044 also includes a processing section portionof working space 1046. This portion of the working space is frontward ofprocessing stations 1071-1073 within the enclosure envelope 1045. Thisprocessing section working space allows the tray conveyor describedbelow to supply and remove loaded wafer trays to and from the processingstations.

Conveyor

Processor 1040 is advantageously provided with a mechanical wafer trayconveyor 2140. Conveyor 2140 will be described initially with referenceto FIGS. 45 and 46. The preferred conveyor includes a conveyor carriageor tram 2156 and a mechanical arm assembly 2157 which is mounted on thetram. The tram moves the mechanical arm assembly along a defined tramtravel path. The mechanical arm assembly moves the wafer trays 1060upwardly, downwardly, inwardly, outwardly, and adjusts the tilt within arange of available positions and orientations.

Tram 2156 has a base 2160 which connects with a base subassembly 2165which forms part of the mechanical arm assembly. The complementary baseparts 2160 and 2165 join to provide a combined base assembly whichserves as a movable base for the mechanical arm assembly.

Tram 2156 moves along a guide track which defines the tram path alongwhich the tram travels. The guide track is advantageously formed byupper and lower guide bars 2158 and 2159 which are mounted along theoutward side of a track support member 2161 forming part of the frame.This construction allows the mechanical arm assembly to extend intocantilevered positions to reach processing stations 1071-1073 with goodpositional stability. The guide bars are engaged by track followers inthe form of linear bearings 2171 which are secured to the inward face ofthe tram base 2160. The linear bearings 2171 are advantageously providedwith rod engaging rollers spaced at equal 120° arc positions about theguide bars 2158 and 2159.

The tram is powered along the defined path guide track by a suitabletram driver, such as a track magnetic drive in the form of linearmagnetic motor 2163. Linear magnetic motor 2163 is most preferably alinear brushless direct current motor. Such a preferred tram driver usesa series of angled magnetic segments which magnetically interact with anelectromagnet on the base of the robotic conveyor to propel the tram andattached mechanical arm up and down the defined path track.

The path position of the base 2160 along the guide track is preciselycontrolled using a positional indicating array (not shown) affixed tothe front of the track support member adjacent to guide bars 2158 and2159. An optical emitter detector pair (not shown) are mounted upon basepiece 2160. The optical emitter detector pair serves as a track positionsensor or indicator which reads the position of the tram base from theindicating array after proper calibration. The positional accuracy ofthe track position indicator is preferably in the range less than 0.003inch (approximately less than 0.1 millimeter).

A forearm assembly is connected near the outer distal end of the upperarm assembly. The forearm assembly advantageously includes two forearms2172 which are joined by a forearm connection member 2174. The forearmassembly also uses opposing face panels 2173 (FIG. 47) to provide astrong and mechanically integrated forearm assembly which is resistantto twisting and provides a high degree of positional stability. Theforearm assembly is connected to the upper arm assembly to allowrelative pivotal movement about an elbow pivot axis 2169.

The distal end portions of the forearm assembly support a hand assembly2176. Hand assembly 2176 is supported in a manner allowing pivotalmovement about a wrist pivot axis 2170. The hand assembly includes twocomplementary hand bars 2177. Hand bars 2177 are joined together by ahand cross piece 2178. The hand assembly also preferably includes a trayengagement tool 2180 which is mounted to the hand cross piece 2178.

FIGS. 48 and 49 show that the preferred tray engagement tool 2180includes a complementary pair of hand extensions 2181. Hand extensions2181 are advantageously semi-cylindrical sections which form a cradlewhich engages the wafer tray 1060. The hand extensions preferably engagethe wafer tray along the side rails, such as along the outer sidesurfaces of the tray. More specifically, the hand extensions preferablyare spaced to define a hand extension gap 2182 having parallel insideengagement edges 2183. Tool engagement edges 2183 are received along thewafer tray side channels 1081. The tool engagement edges are slidlongitudinally along side channels 81 to position the tool forengagement with the wafer tray.

The ends of the hand extensions are preferably provided with end tines2184. When the hand extensions are lifted upwardly, the engagement edgesbear upon the downward facing bearing surface 1082 of the wafer sidechannels. Simultaneously therewith, tines 2184 move upwardly to latch atthe end of the wafer tray to prevent longitudinal slippage of the wafertray upon the hand extensions. This latching places the tines along endsurfaces of the wafer tray. The hand extensions can advantageously beprovided with perforations 2185 to lighten the weight of the assembly.

FIG. 33 Operation and Methods

The operation and methodology of processor 1040 have in part beenexplained above. Further description will now be given.

The invention further includes novel methods for processingsemiconductor wafers and similar units requiring extremely lowcontamination. The methods can include providing a suitable processor,such as processor 40 described herein above and the associatedsubsystems thereof. Novel methods of processing such units preferablyare performed by loading the wafers or other units to the system incarriers, such as wafer carriers 1051. Such loading step is to a workspace which is enclosed or substantially enclosed, such as working space1046. The loading step can include opening an enclosure door, such asdoor 1059 of the interface port to allow entry of the wafers. Theloading preferably is done by opening the enclosure door and extending aloading shelf through an open interface opening, such as port 1056.Positioning of the loading shelf can be accomplished by moving the firstcarriage outwardly into an extended loading position.

The loading is further advantageously accomplished by depositing thewafers held within wafer carriers onto an extended loading shelf whichis positioned through the interface opening. The wafers held in thecarriers are positioned by depositing the loaded wafer carriers onto theextended shelf. The first carriage is thereafter moved such as byretracting the first carriage and the extended cantilevered shelf. Afterretracting the shelf through the interface port the methodsadvantageously include closing the interface port door or other similarenclosure door.

The methods also preferably include transferring wafers to a wafer tray,such as tray 1060. Such transferring preferably is done by transferringthe wafer from a wafer carrier and simultaneously onto the wafer tray.This is done by lifting the wafers from the wafer carrier using thewafer tray. The transferring is advantageously accomplished by extendingthe wafer tray through an opening in the wafer carrier, for exampleelevating the wafer tray up through a bottom opening in the wafercarrier to lift the wafers. The transferring preferably is accomplishedusing an array of wafer receivers, such as receivers 1066. The waferreceivers which receive the wafers are preferably spaced and parallel toallow the receivers of the tray to be extended to receive the wafers inan edgewise relationship. The receiving is most preferably done usingreceiving channels having converging side surfaces which perform aguiding function as the tray and wafers approach relative to oneanother. The receiving also advantageously includes positioning edges ofthe received wafers into receiver bottom sections 1068 which includespositioning the edges into slots having spaced approximately parallelreceiving slots with surfaces along marginal edge portions which holdthe wafers in a spaced substantially parallel array.

The transferring also preferably includes extending, such as by lifting,the wafers received upon the wafer trays so as to clear the wafer freeof the wafer carriers. This clearing of the wafers installed upon thetrays completes the transferring of the wafers to perform an installingof the wafers onto the wafer trays.

The transferring and installing operations can in the preferredembodiment be preceded by storing wafer trays in a wafer tray storagearea or array. The wafer trays can be stored by slipping the wafer traysinto storage receptacles, such as upon storage support ledges 2109. Thestoring can occur by vertically arraying the unloaded wafer trays.

The wafer trays held within the storage receptacles are also preferablyremoved by unloading therefrom. This unloading can advantageously bedone by elevating or otherwise by extending a tray support, such as head2129 into proximity to and then engaging the head with the tray. Theextending can function by lifting the engaged head and then moving todislocate the lifted tray from the storage area. This dislocating canmost easily be accomplished by moving the storage area, such as bymoving the second carriage 2102, most preferably by retracting thecarriage.

The steps preceding the transferring step can also advantageouslyinclude passing the engaged wafer tray through a pass-through opening inthe first carriage. The passing-through step can be accomplished bylowering or retracting the engaged wafer trays through the passthroughopening and thus placing the wafer tray in a position suitable forperforming the transferring. The passing-through most preferablyincludes aligning the engaged wafer tray with the pass-through opening.

The steps preceding the transferring and installing process alsopreferably include relatively moving the engaged wafer trays relative tothe wafer carriers to bring the engaged wafer trays into alignedposition. This aligning step is most ideally done by retracting orotherwise moving the first carriage rearwardly until the wafer carrieropening and engaged wafer tray are aligned for transfer andinstallation.

After the transferring or other installing of the wafers onto the wafertrays, the loaded wafer trays are preferably inventoried, such as byholding upon the second carriage. This storing is in the preferredembodiments done by extending or otherwise moving the second carriage orother loaded tray storage relative to the loaded wafer trays. The loadedwafer trays can be stored by positioning them over a holding featuressuch as holding receptacles 2125. The positioning can be followed bylowering the wafer trays into the holders and then supporting the wafertrays by the wafer holders.

The loaded wafer trays can then be processed further by loading thewafer tray onto a wafer conveyor, such as conveyor 2140. The loadingonto the conveyor can be done by moving a wafer tray engagement toolinto engagement with the tray. This engaging step is most preferablydone by sliding portions of the wafer engagement tool along receivingfeatures of the wafer tray, such as by sliding the engagement edges 2183along receiving channels 1083 of the tray, most preferably alongopposing sides of the wafer tray. The engaging can further be perfectedby lifting or otherwise interengaging the wafer tray engagement toolwith the wafer tray being moved. This is most preferably done by liftingthe tool relative to the tray and thereby positioning a longitudinalengagement feature, such as tines 2184, against a complementary surfaceof the tray so that longitudinal or other lateral displacement of thetray upon the tool does not occur due to movement.

The methods also preferably include moving the wafer trays to one ormore processing stations. The moving can be done by tramming the loadedwafer tray along a defined guide track upon a movable tram. The movingor conveying step can also include horizontally positioning the wafertray, and vertically positioning the wafer tray, and orienting theangular orientation of the wafer tray to enable the wafer tray to bepositioned into a processing chamber. This functioning is preferablyfollowed by loading the wafer tray into the processing chamber. Thisloading can be done by inserting the loaded wafer tray into acentrifugal wafer tray rotor. The inserting or other loading step canbest be accomplished by sliding the loaded wafer tray into an engagedrelationship with the rotor by receiving interengaging parts of therotor and wafer tray.

The wafers which were inserted or otherwise installed into theprocessing chamber are then preferably further treated by processingwith fluid processing materials, such as chemical processing fluids,liquid or gas; or heating, cooling or drying fluids, most typicallygases.

The processing can also advantageous be centrifugal processing whichinvolves rotating or otherwise spinning the wafers being processed,particularly when still installed upon the wafer trays. The spinningpreferably occurs with the wafers positioned within a rotor whichperforms a restraining function keeping the wafers in an aligned arraycentered near the axis of rotation. The centrifugal processing caninclude a variety of spinning, spraying, rinsing and drying phases asdesired for the particular articles being processed. Additionalpreferred processing parameters are included in the appendix hereto.

The processing can also include immersion processing, such as can beperformed by the immersion processing station 2414 described above.Immersion station 2414 or other suitable station can perform processeswhich include positioning a dipper so as to allow installation of aloaded wafer tray thereon. As shown, this is down by raising the dipperarm upwardly and positioning the wafer holding basket with an open sideforwardly. The mechanical arm can then function by inserting orotherwise installing or loading the basket with an open receiver foraccepting the loaded wafer tray. After insertion and loading of thewafer tray onto the dipper movable assembly, then the dipper arm is usedby moving the held wafers on the trays so as to process the wafers inthe desired immersion tank. This dipping or immersing operation ispreferably a submersing step which places the entire tray of wafers intothe bath of processing chemical. Thereafter the wafers are processed byholding the wafers in the desired immersion position and conduction anymonitoring desired while performing the bath processing.

The immersion processing methods can further include withdrawing thebathed wafers, such as by lifting the dipping arm upwardly. The waferholding head is then preferably removed from the bath and is held in adraining condition to allow processing liquids to drain back into thebath from whence they were removed. The immersion processing can then berepeated for the second or other subsequent processing bath. After thebathing processes have been finished at any particular station then themechanical arm is used by unloading the wafer trays from the dippers andthe loaded wafer trays are moved to the next desired processing station.

The methods of this invention also include unloading the wafer traysfrom the processing stations, such as by engaging the loaded wafer trayswith a tray engagement tool in processes similar to those discussedabove. The engaged and loaded wafer tray is then preferably processed byrelocating the wafer tray to a second processing station, such as byconveying by moving with the mechanical arm assembly. The relocating caninclude withdrawing the wafer tray from the processing chamber andmoving to another processing chamber and installing the wafer traytherein. The processing can then be furthered using a processingsequence similar to that described or in other processing steps desired.

The wafer trays are also handled by conveying the wafer trays andsupported wafers to a holding station and holding the wafers thereat.The holding awaits an interface unloading sequence which can beaccomplished by transferring the wafer trays and supported wafers fromthe wafer trays back to wafer carriers. The transferring orretransferring step back to the wafer carriers is essentially a reverseof the transferring and installing steps described above. Suchadvantageously includes unloading the wafer trays from the holding area,such as by lifting loaded wafer trays from the holding receptacles. Thelifting or other removing of the wafer trays from the holders isadvantageously done by extending an elevator head through an alignedwafer carrier and elevating the wafer trays. The holders are then movedin a relative fashion from the lifted or otherwise supported wafertrays. This is advantageously done by moving the second wafer carriage,such as by retracting the wafer carriage rearwardly away from thesupported wafer trays. The relative moving of the removed loaded wafertrays and holders allows the wafer trays to be lowered or otherwiseretracted. The retracting is best performed by lowering the wafer traydownward after aligning the wafer tray with a wafer carrier. Thelowering causes a transferring of wafers from the wafer trays onto thewafer carrier.

The methods also preferably include retracting the elevators downwardlyand beneath the first carriage with the supported and now unloaded wafertrays thereon. The first carriage can then be moved into thepass-through position by aligning the empty wafer tray with thepass-through opening. The empty trays can then be extended, such asupwardly, through the pass-through opening.

The methods then preferably include moving the transferred wafers heldin the wafer carriers into an extended unloading position through theinterface port. This is advantageously done by moving the first carriageforwardly and extending the cantilevered shelf out through the interfaceport.

The moving of the first carriage forwardly to accomplish unloading, canalso be used to perform a storing function for the empty wafer traysinto the empty wafer storage array. This is preferably done by elevatingthe wafer trays into an aligned storage position, such as at a desiredaligned storage elevation and then moving the first carriage andattached storage gallery toward the engaged empty wafer tray. Onceinstalled the empty wafer tray can be lowered into a storage position.The empty wafer trays are preferably stored in a downwardly progressingfashion when the elevator is used.

The wafer carriers and associated processed wafers are taken from theprocessor by removing the loaded wafer carrier from the cantileveredshelf after such has been extended out through the interface port orother unloading passageway. This is typically done by manually graspingthe wafer carrier with the processed wafers therein.

In compliance with the statute, the invention has been described inlanguage more or less specific as to structural and methodical features.It is to be understood, however, that the invention is not limited tothe specific features shown and described, since the means hereindisclosed comprise preferred forms of putting the invention into effect.The invention is, therefore, claimed in any of its forms ormodifications within the proper scope of the appended claimsappropriately interpreted in accordance with the doctrine ofequivalents.

1. A method for moving wafers within an automated wafer processingsystem, comprising the steps of: supporting an array of wafers at asupport location; moving a robot having an engagement implementhorizontally in a first direction, to a position where the engagementimplement is vertically below the wafers to be moved; moving the robotvertically upwardly, to bring the engagement implement into contact withthe wafers; lifting the wafers vertically upwardly, so that the wafersare supported on the engagement implement; moving the engagementimplement horizontally in a second direction, opposite to the firstdirection, to carry the wafers away from the support location; movingthe robot to position the engagement implement supporting the wafersinto alignment with a rotor; moving the robot horizontally to bring theengagement implement supporting the wafers into the rotor; moving theengagement implement vertically downwardly to set the wafers onto rotorsupports in the rotor; and withdrawing the engagement implement from therotor.
 2. The method of claim 1 wherein the wafers are supported atopposing side edges at the support location.
 3. The method of claim 1wherein the robot moves the engagement implement via an upper robot armpivotably attached to a lower robot arm.
 4. The method of claim 1further comprising the steps of spinning the rotor loaded with waferswithin a process chamber and spraying a liquid onto the spinning wafers.5. The method of claim 1 further comprising the step of securing thewafers in place within the rotor by pivoting a retainer assembly on therotor into contact with the wafers.
 6. The method of claim 1 wherein thewafers are equally spaced apart from each other at the support location.7. The method of claim 4 wherein the wafers are in a near verticalposition while spinning in the process chamber.
 8. An automated waferprocessing system, comprising: a support for supporting an array ofwafers at the edges of the wafers; a robot having an engagementimplement for engaging and lifting wafers, with the robot having meansfor moving the engagement implement horizontally, vertically, and in acircular pivoting movement; a process chamber; a plurality of spraynozzles in the process chamber; and a rotor for receiving the array ofwafers and for holding the array of wafers at the edges of the wafers,while the wafers are rotated within the process chamber.
 9. The systemof claim 8 further comprising a retainer assembly pivotably attached tothe rotor for retaining the wafers during rotation.
 10. The system ofclaim 8 wherein the rotor holds the wafers in a near vertical positionwhile spinning in the process chamber.
 11. An automated wafer processingsystem, comprising: a process chamber; a plurality of spray nozzles inthe process chamber; support means for supporting an array of wafersbefore and after processing; rotor means for rotating the array ofwafers within the process chamber, while the wafers are sprayed with aliquid from the spray nozzles; and robot means for engaging and liftingwafers, and for moving the wafers horizontally, vertically, and in acircular pivoting movement, between the support means and the rotormeans, for loading and unloading the wafers into and out of the rotormeans.
 12. The system of claim 11 further comprising retainer meansassociated with the rotor means for retaining the wafers duringrotation.